Manitoba Rocks! HOME KIDSROCK TEENSROCK NEWS GEOTOURS

Dig It!

DIG IT! Mineral Information

What on Earth's under your feet in Manitoba?

Check out the tables below to view detailed information on minerals and rocks. Click the thumbnails on the left side to view larger images. Then click the name below each thumbnail image and watch the right side automatically scroll to detailed text about that particular rock or mineral!

Legend:

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Igneous

Igneous

Metamorphic

Metamorphic

Sedimentary

Sedimentary

 

     

AMBER

Mineralogy: A fossilized tree resin

Did You Know?

• Found around the world

• May contain remnants of insects -- the movie "Jurassic Park" used the premise that dinosaur DNA could be recovered from a mosquito that had been trapped in amber during the Jurassic (or Cretaceous), which then could be used to reconstitute the otherwise extinct Tyrannosaurus Rex and other dinosaurs

• First reported in Canada by geologist Joseph Burr Tyrrell in 1891, in beaches located along the west shore of Cedar Lake in western Manitoba

• Amber was once collected in bulk, and became submerged due to construction of a hydro dam at Grand Rapids in 1965. Recently, Cedar Lake amber or 'Chemawinite' has resurfaced with wave action due to its light specific gravity (1.05 to 1.09) in Manitoba along Cedar Lake.

• Uses: valued as a gemstone, and has been used for varnish.

Rock Type:
Sedimentary

 


ANORTHITE (Ca-Feldspar)

Mohs scale: 6

Group: Silicate

Formula: CaAl2Si2O8

Crystal System: Triclinic

Specific Gravity: 2.76

Did You Know?

Rare calcium endmember of plagioclase feldspar, a rock-forming mineral that makes up a large part of the Earth's crust - also found on the moon and in comets

Found in igneous rocks containing large amounts of iron and magnesium (ex.: 'gabbro') - large amounts found on Manitoba's Precambrian Shield

• Uses: ceramics, decorative stones

Rock Type:
IgneousMetamorphic

 


AUGITE

Mohs scale: 5-6

Group: Silicate

Formula: (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6

Crystal Habit: Monoclinic, prismatic

Specific Gravity: 3.2–3.3

Colour: Dark green to black

Streak: Green-grey or light to dark brown. Produces brittle fragments on streak, instead of powder

Did You Know?

• Augite is the most abundant of the primary igneous Precambrian pyroxene minerals

• Widespread occurrence in Manitoba including north end of Ospwagan Lake, north of Thompson, where short tabular crystals 2–3 mm in length in pyroxenite give the rock an interlocking texture

• Fine crystalline structure

• Rare variety of pyroxene, 'jadeite', is highly valued as 'jade', an ornamental stone

• Uses: popular as a gemstone

Rock Type:
IgneousMetamorphic

 


BASALT

Mineralology: Olivine, pyroxene and plagioclase

Did You Know?

• Ginely-crystalline 'mafic' volcanic rock, formed on the Earth's surface from rapidly extruded (quickly squeezed out) and cooled lava

• Most common, widespread rock on Earth (part of the oceanic crust)

• Amazing type of basalt (referred to as 'pillow lavas') forms where lava erupts or explodes under water, like that occurring presently offshore in the Hawaiian islands

• Ancient (2 to 4 billion years old) pillow lavas found throughout the Precambrian Shield in Manitoba proves that very large submarine volcanoes were present at different times in Manitoba's geological history!

• Uses: aggregate and minor ornamental stone and building materials

Rock Type:
Igneous

 


BENTONITE

Group: Phyllosilicate (Smectite group)

Did You Know?

• Manitoba bentonite was carried as volcanic ash high in the atmosphere from Montana, USA about 145–66 million years ago (during the Cretaceous Period)

• The ash settled in a shallow interior marine seaway where it was devitrified and altered into clay minerals — montmorillonite, illite, and smectite

• Indigenous people extracted bentonite for use as soap. Early pioneers used it as a weather-protecting material on log cabins

• Calcium bentonite (non-swelling) was quarried from the Cretaceous Pembina Member of the Pierre Shale, west of Morden and Miami, Manitoba, by Pembina Mountain Clays Limited from 1939 to 1990

• Uses: as an absorbent of impurities in industry such as removing vegetable matter from canola oil or metallic impurities from engine oil. Also used in make-up and toothpaste

Rock Type:
IgneousSedimentary

 


BIOTITE

Mohs scale: 2.5-3

Group: Silicate

Formula: K(Mg,Fe)3(AlSi3O10)(F,OH)2

Crystal Habit: Massive to platy, monoclinic

Specific Gravity: 2.8–3.2

Colour: Black, brown, red-brown or green

Streak: White

Did You Know?

• A very common magnesium-iron mineral in Manitoba (appears as 'flakes' in Precambrian rocks, example: granite)

• Most abundant as biotite schist (a metamorphic or altered sedimentary rock) which can be found on the east and west shores of West Hawk Lake in southeast Manitoba, and east and northeast of Wekusko Lake in west-central Manitoba

• Uses: as a filler/extender in paints, mold-release filler in rubber, drill mud additive, non-stick surface in asphalt shingles, roofing materials

Rock Type:
IgneousMetamorphic

 


CALCITE

Mohs scale: 2.5-3

Group: Carbonate

Formula: CaCO3

Crystal Habit: Crystalline, granular, stalactitic, concretionary, massive, rhombohedral; trigonal, hexagonal, scalenohedral

Specific Gravity: 2.71

Colour: Colourless or white, also grey, yellow, green

Streak: White

Did You Know?

• The most important rock-forming industrial (non-metallic) mineral in Manitoba

• Occurs in 330 to 420 million year old (Phanerozoic) 'calcareous' (mostly calcium carbonate) sedimentary rocks (example: limestone) which can be found in the Western Canada Sedimentary Basin of southwestern Manitoba; also found within the Hudson Bay Basin in the northeastern portion of the province

• Many Manitoba roads contain calcite obtained from high calcium (>95% CaCO3) limestone quarries in the Interlake area (near the east shore of Lake Manitoba and near Dawson Bay on Lake Winnipegosis) that was used to produce Portland cement for concrete (in Winnipeg and Regina) until 1990

• Since 1969, Graymont Western Canada Inc. (and predecessor companies) have quarried high-calcium limestone near Moosehorn, Manitoba (3 km from the east shore of Lake Manitoba). The stone is calcined in the adjacent Faulkner plant to produce high-calcium lime (CaO), which is used in the construction, steel and pulp and paper industries; as a major acid neutralizing agent; flue-gas desulphurization; in wastewater treatment; and as a water softener

• Clear, transparent crystals of calcite (found in high-grade deposits located mainly in Iceland) known as Iceland spar are used in optical instruments

• Uses: calcium source for animal feed and poultry grits; aggregate; concrete ingredient; polished limestone and marble in prestige architecture

Rock Type:
IgneousSedimentary

 


CHALCOPYRITE

Mohs scale: 3.5-4

Group: Sulphide

Formula: CuFeS2

Crystal Habit: Tetragonal

Specific Gravity: 4.1–4.3

Colour: Brass-yellow

Streak: Greenish-yellow

Did You Know?

• Important ore of copper, found in Precambrian greenstone belts in Manitoba

• Manitoba's first and highest grade chalcopyrite (copper ore averaging 19.79% Cu) mine, the Mandy Mine, was located on Schist Lake, southeast of Flin Flon (1916-1919). The ore body was too small for an on-site smelter. Ore was hauled by winter road, then by boat and rail to Trail, British Columbia

• In 2014, Manitoba produced 5.8% of Canada's copper (38 198 tonnes worth $290 875 000) from mines owned by Hudbay Minerals Inc. in the Flin Flon-Snow Lake area, and Vale Canada Ltd. near Thompson

• Copper was first used in coins and ornaments starting about 8000 B.C. At about 5500 B.C., copper tools helped civilization emerge from the Stone Age

• The Statue of Liberty in New York city represents the largest use of copper in a single structure; copper covered domes can be found on many churches in Winnipeg

• Uses: building construction; power generation and transmission; house and office electrical wiring; water pipes; heating and cooling systems; telecommunications; electronic product manufacturing; production of industrial machinery and vehicles

Rock Type:
IgneousMetamorphic

 


CHLORITE

Mohs scale: 2-2.5

Group: Silicate

Formula: (Mg,Fe)3(Si,Al)4O10(OH)2•(Mg,Fe)3(OH)6

Crystal Habit: Monoclinic

Specific Gravity: 2.6–3.3

Colour: Varied shades of green, yellow, white pink, rose-red

Streak: Greenish, green-black, white

Did You Know?

• A widespread soft green ferromagnesian secondary rock-forming mineral, common to Precambrian metamorphic rock

• Formed by alteration of clay minerals, pyroxenes, amphiboles and micas into chlorite schist, a dark green rock that is composed mainly of chlorite

• Chlorite is present in schist off the eastern shore of Black Island, Lake Winnipeg, on the western part of Reed Lake, and is host rock for some ore bodies at Flin Flon, Chisel Lake, Anderson Lake and Stall Lake mines (Snow Lake area)

• Uses: as a filler and as a constituent of clay (limited industrial use)

Rock Type:
Metamorphic

 


CHROMITE

Mohs scale: 5

Group: Oxide (Spinel group)

Formula: FeCr2O4

Crystal Habit: Isometric

Specific Gravity: 4.6

Colour: Dark grey to black (or brownish-black, which is rare)

Streak: Dark brown

Did You Know?

• The only ore of chromium, occurring as non-magnetic disseminated grains and granular masses in Precambrian ultramafic rocks and serpentinites in Manitoba

• Highly heat-resistant

• Extensive deposits drilled in Manitoba's Bird River area could be used to produce a ferrochrome-nickel master alloy (to replace stainless steel scrap in the production of stainless steel)

• Manitoba's Bird River chromite deposits, within a gabbro-peridotite sill, form one of the largest low grade (26% Cr2O3) chromite deposits in North America (chromium to iron ratio, 1.4:1), but the low ratio has inhibited mining activities to date

• Uses: in chrome plating for corrosion-resistant, very hard super-alloys and stainless steel

Rock Type:
Igneous

 


CORDIERITE

Mohs scale: 7-7.5

Group: Silicate

Formula: (Mg,Fe)2Al4Si5O18

Crystal Habit: Orthorhombic - Dipyramidal

Specific Gravity: 2.57–2.66

Colour: Blue, smoky blue, blue-violet, green, yellow-brown, grey

Streak: White

Did You Know?

• Is a complex silicate of magnesium and aluminum with hydroxyl and variable amounts of iron

• Abundant in Precambrian metamorphic rock (contact hornfels and in cordierite schist and gneiss) in Manitoba. It occurs frequently with garnet in altered sedimentary (or occasionally in volcanic) rocks and is also found in pegmatite that has intruded them

• Usually some shade of blue, but has 'pleochroic' properties (appears different colors (from blue to dark blue and straw yellow) when viewed at different angles). This property was known to the Vikings and was used by them to locate the sun through overcast skies for navigational purposes

• A gem variety, 'iolite', has been documented near Walton Lake, and an unusual smoky green-blue variety in the Snow Lake area

• A deep blue cordierite can be found in Paint Lake Recreational Park area. Removal of this cordierite is prohibited without provincial park authority approval

• Uses: few industrial applications; may be used as a gemstone because of its attractive colours, hardness and lack of easy cleavage; although brittle, it does not fracture easily

Rock Type:
Metamorphic

 


DOLOMITE

Mohs scale: 3.5-4

Group: Carbonate

Formula: CaMg(CO3)2

Crystal Habit: Tabular crystals (curved face, columnar, stalactitic, granular, massive, trigonal)

Specific Gravity: 2.85

Colour: Colourless or white, pink, grey, green, brown, black

Streak: White

Did You Know?

• Common rock-forming mineral in Ordovician and Silurian rock of Manitoba

• Major component of dolomitic limestone and dolostone (also referred to, by some, as dolomite) present in the Western Canada Sedimentary Basin of southwestern Manitoba and within the Hudson Bay Basin in the northeastern portion of the province

• Valued as a reservoir rock for oil and gas because of its increased porosity and permeability

• Pure dolomite (less than 1% impurities) is found in Manitoba's Interlake area and considered a potential source for the production of manganese metal, one of Earth's lightest-weight metals

• Dolime was produced from dolomite quarried at Stonewall from 1880 to 1965 by the Winnipeg Supply and Fuel Company Limited

• Since 1977, Graymont Western Canada Inc. has quarried high-purity dolostone near Hibre, Manitoba. The stone is also calcined at its Faulkner plant to produce dolime (MgO), which is used in plaster, in exterior cement stucco mixes, as an additive to soil and peat mixtures, fertilizers, refractories, pharmaceuticals, glass, and magnesium chemical feedstock

• A dolomitic limestone known as Tyndall® stone has been quarried for over 100 years at Garson, Manitoba. The distinctively mottled "tapestry stone" has been used as a building and dimension stone across Canada, eg. Manitoba Legislative Building (and in many cases, around the world)

• Uses: for aggregate in cement and asphalt; chemical desulphurization of iron and steel; reducing agent in the production of Be, Ti, Zr, Hf and U

Rock Type:
Sedimentary

 


GALENA

Mohs scale: 2.5

Group: Sulfide

Formula: PbS

Crystal Habit: Cubic or octahedral crystals; isometric

Specific Gravity: 7.4–7.6

Colour: Lead grey

Streak: Lead grey to black

Did You Know?

• An ore of lead (also mined for silver), found in Precambrian greenstone belts in Manitoba

• Lead (Pb) is the element contained in galena ore (not related to 'lead' in pencils, which is carbon, from the mineral graphite)

• First mined in Manitoba in 1959 during development of the Chisel Lake Mine, located near Snow Lake

• Although "spharlerite/galena" has been known to occur in igneous and metamorphic rocks in Manitoba since the early 1900s, it was first discovered in sedimentary rock (dolomite of the Cedar Lake Formation within the Silurian Interlake Group) in 2004 in the north basin of Lake Winnipegosis, near the northeast end of Pemmican Island

• Uses: shielding from radiation (example: lead-lined jackets worn when an x-ray is taken); wireless communications; lead-containing materials such as gasoline, batteries, bullets, alloys; in solder and as roofing material

Rock Type:
IgneousSedimentaryMetamorphic

 


GARNET

Mohs scale: 6.5-7.5

Group: Silicate

Formula: (Mg, Fe, Mn, Ca)3 (Al, Fe, Cr)2(SiO4)3

Crystal Habit: Isometric, rhombic dodecahedron

Specific Gravity: 3.5–4.3

Colour: Orange, green, yellow, purple, black, brown, dark red (never blue)

Streak: Colourless

Did You Know?

• Represents a group of aluminum, magnesium, iron, manganese, calcium or chromium silicate rock-forming minerals

• Garnet occurs widely in metamorphic rocks throughout the Precambrian regions of Manitoba

• The most abundant type of garnet is almandine, a brownish red iron-aluminum garnet found in mica schist and gneiss. It is used in industrial applications as an abrasive because of its hardness and its splintery fracture, which provides sharp cutting edges

• Occurs as pink sand grains (naturally concentrated by wave action), on west shore of Clearwater Lake, near The Pas, Manitoba

• Large (5 cm) non-gem quality deep red crystals were found during mining of Hudbay Minerals Inc.'s former Chisel Lake ore body near Snow Lake. Also, at File Lake (21 km west of Snow Lake) deep red, almost perfectly formed garnet crystals (0.5 to 2 cm) weather out on the surface of staurolite-sillimanite schist and paragneiss

• Uses: water filtration, water jet cutting, abrasive powders, sandpaper, sandblasting, and as a dark red gemstone

Rock Type:
IgneousMetamorphic

 


GOLD

Group: Native metal

Formula: Au

Did You Know?

• A transitional metal and element, produced as a by-product of Precambrian base metal mining by Hudbay Minerals Inc. in Flin Flon and by Vale Canada Ltd. in Thompson; and until recently by several Precambrian gold mines in the Rice Lake and Flin Flon-Snow Lake greenstone belts

• Manitoba's first major gold discovery was in 1911 at Rice Lake, the current site of the town of Bissett

• Found in low-to-high temperature hydrothermal veins in metamorphic rocks, or associated with granitic igneous rocks, and as heavy mineral concentrates in some sedimentary rocks

• Present in seawater, but in such low concentration it is uneconomical to recover it

• Uses: coinage, jewellery, dentistry, medicine, electrical conductivity, computers, infrared shielding, glassware, gold leaf

Rock Type:
IgneousSedimentaryMetamorphic

 


GRANITE

Mineralogy: Often consists of quartz, feldspar and biotite (mica)

Did You Know?

• Commonly found in the Earth's continental crust

• Forms deep underground as magma slowly cools, allowing coarse crystals or 'grains' to form

• The name 'granite' is from a Latin word granum, meaning 'grain'

• Granite products have been produced from the Precambrian Lac du Bonnet batholith in Manitoba since 1958 by Cold Spring Granite (Canada) Ltd., near Lac du Bonnet

• Uses: aggregate, building stone, decorative countertops, floor tiles, memorial stones, monuments

Rock Type:
Igneous

 


GRAPHITE

Mohs scale: 1-2

Group: Native non-metal

Formula: C

Crystal Habit: Hexagonal

Specific Gravity: 2.23

Colour: Black

Streak: Black

Did You Know?

• Is black to steel-grey in colour, has a black streak and a metallic lustre

• Graphite found in Manitoba is generally in Precambrian metamorphic rock, such as schist, gneiss and recrystallized limestone

• Large high-grade graphite deposits were found in Manitoba (April 2014) by Callinex Mines at their Neuron Graphite property near Thompson

• The element carbon (C) is used for so called 'lead' pencils, which actually don't contain any lead (Pb) but do consist of graphite mixed with fine clay

• Uses of graphite: very efficiently conducts heat and electricity; facings for foundry-moulds; in refractory crucibles for the steel, brass and bronze industries; in electro-plating; in commutators, and as electrodes for the electric furnace

• Manufactured pure carbon in the form of very thin, nearly transparent sheets known as 'graphene' is lightweight and remarkably strong

• Uses of graphene: future uses of graphene may include paper-thin TV or computer tablet screens, folded and carried in your pocket!

Rock Type:
Metamorphic

 


GYPSUM

Mohs scale: 2

Group: Sulfate

Formula: CaSO4•2H2O

Crystal Habit: Massive, twinned flat crystals, elongated, prismatic, monoclinic

Specific Gravity: 2.32

Colour: Clear, colourless white, grey, yellow, red, brown

Streak: White

Did You Know?

• Gypsum is the main commercial calcium sulphate mineral, and was the first industrial mineral to be quarried in Manitoba

• The evaporite deposits of gypsum in Manitoba were laid down as saline residues (calcium sulphate) during the Jurassic period, about 150 million years ago

• Gypsum was quarried in from 1901 to 1990 by Manitoba Union Mining Co. (and later, Georgia-Pacific Canada, Inc.) at Gypsumville (only Manitoba community named for a local mineral)

• Mined underground by Westroc Industries Limited (1930-1962) and BACM (1967-1970) at Amaranth, (southwest Lake Manitoba); also mined by Westroc south of Winnipeg near Ste. Agathe (Silver Plains, 1964-1975)

• CertainTeed Gypsum (and predecessor companies) have quarried gypsum near the former community of Harcus, since 1978. Almost daily, the gypsum is transported by truck to its wallboard plant on 1200 Empress Street in Winnipeg. At the plant, the gypsum is crushed and calcined to make plaster. Wallboard (drywall, sheetrock or plasterboard) is a "sandwich" of plaster (and added water) between two sheets of heavy paper, which is then solidified by heating

• Plaster of Paris is produced when water is added to calcined gypsum. The process of calcination (heating) drives off ¾ of the water content of gypsum, leaving an interlocking mass of needle-like gypsum crystals

• Crystal 'rosette' chunks of gypsum ('selenite', probably deposited by groundwater) have been found around Manitoba's floodway, and as rhombohedral-bladed selenite crystals in black shale beds (probably the result of disassociation of pyrite near Morden, Dauphin, and Swan River

• Other uses: mortar; retarder to prolong the set of Portland cement; construction pipes; plaster of Paris ingredient (medical surgery/dentistry); stucco; binding ingredient (baked goods); vitamins (dietary calcium); fertilizer; soil conditioner; insecticide carrier

• Note: 'Selenite' sounds like the element 'selenium', however the two are not related

Rock Type:
Sedimentary

 


HALITE

Mohs scale: 2.5

Group: Halide

Formula: NaCl

Crystal Habit: Isometric

Specific Gravity: 2.16

Colour: Colourless or white, impurities may produce any colour (often yellow, grey, black, brown, red)

Streak: White

Did You Know?

• Halite, also known as 'rock salt', was the first commercially-developed mineral to be produced for local consumption at Monkman's salt works (situated north of the town of Winnipegosis) in Manitoba

• Produced by the evaporation of brine springs, halite was used to preserve meat and fish during the fur trade from 1818 to 1874. The springs probably originate at depth from dissolution of salt beds by groundwater within the Western Canada Sedimentary Basin of southwestern Manitoba

• A small amount of salt was produced by the Northern Salt Company, Limited from a brine spring near Dawson Bay on Lake Winnipegosis in 1941

• The Canadian Salt Company produced salt at Neepawa using the vacuum pan evaporating process starting in 1932. Annual production ranged from 18 100 to 22 700 tonnes. The salt was recovered from salt brines, containing 170 000 to 180 000 ppm total dissolved solids, pumped from two wells in the Devonian Winnipegosis and Souris River Formations at depths of 548 and 455 m, respectively. The plant became uneconomic and closed in 1970 due to cheaper salt obtained as a by-product from solution mining of potash in Saskatchewan

• A salt spring along the Pelican Rapids Road near German Creek, northeast of Mafeking, has been used by NASA as a model for possible moisture found on the planet Mars

• Salt springs can be visited a few kilometres north of the community of Winnipegosis

• Halite has been mined in the subsurface by salt solution from the Devonian Prairie Evaporite since 2002 by ERCO Worldwide (a division of Superior Plus Inc.), near Hargrave, Manitoba, to produce sodium chlorate (used in the pulp and paper industry, where it contributes alkalinity)

• Other uses: canning; meatpacking; baking; flour processing; animal feedstuffs; steel plate cleaning; aids in solvent extraction; important chemical feedstock

Rock Type:
Sedimentary

 


HEMATITE

Mohs scale: 5.5-6.5

Group: Oxide

Formula: Fe2O3

Crystal Habit: Trigonal, hexagonal, scalenohedral

Specific Gravity: 5.26

Colour: Black to steel-grey to silver; red to red-brown, to black

Streak: Red to red-brown

Did You Know?

• Worldwide, the most important of the iron-ore minerals, forming huge deposits in sedimentary rocks of all ages many of which were enriched by post-depositional metamorphic or oxidation processes

• The earliest excavated or 'mined' Precambrian mineral in Manitoba, much of it in the form of 'agglomerated' (a rock composed of volcanic fragments of various sizes and degrees of angularity) or 'botryoidal' masses of 'concretionary' hematite or turgite

• Note: Botryoidal comes from the Greek word "botrus", which literally means a cluster or bunch of grapes. In geology, the word is often used to describe a rock texture or mineral. 'Concretionary' often refers to a rounded mass of mineral matter found in sedimentary rock discovered by Aboriginal people and used as paint pigment

• From drilling conducted in 1943, it has been inferred that the hematite (ferric oxide) at Black Island (now located within Hecla-Grindstone Provincial Park) formed when ferric (limonitic) hydroxide was dehydrated beneath Ordovician sandstone. The capping of limonitic gossan had previously formed from weathering of Precambrian graphitic schist, which contained abundant pyrite

• In 1739, Louis-Joseph, youngest son of explorer La Vérendrye, visited the Red Cliff 'mine' at Black Island on Lake Winnipeg

• In 1855, 5.4 tonnes of extracted hematite was shipped from Red Cliff by sailboat to Winnipeg, and to Chicago by rail, where a rail car wheel was cast

• The best known hematite deposits in the world (varying from hard specular hematite to soft red earthy types) are the enormous Lake Superior iron formation (Mesabi Iron Range), found just south of the U.S. border at Hibbing, Minnesota

• Uses: as an ore of iron for steel production; as a pigment in paint and stain; printing ink; plastic and rubber; paper; concrete, mortar, brick and tile; ceramic glazes and frits; animal and pet food; pharmaceuticals and cosmetics. Also used as a semi-precious gemstone. Specular hematite also provides some protection against corrosion

Rock Type:
IgneousSedimentaryMetamorphic

 


HORNBLENDE

Mohs scale: 5-6

Group: Silicate

Formula: (Ca,Na)2-3(Mg,Fe,Al)5Si6(Al,Si)2O22(OH,F)2

Crystal Habit: Granular, hexagonal, monoclinic

Specific Gravity: 3-3.4

Colour: Black, dark green, dark brown

Streak: White, colourless

Did You Know?

• Common rock-forming ferromagnesian mineral member of the amphibole group

• Known as 'hornblendite' when it forms almost 100% of a 'plutonic' rock (rock crystallized from the cooling of magma below the earth's surface, eg. diorite, syenite, gabbro, andesite and basalt); and as amphibolite, in metamorphic rock (eg. hornblende schist and hornblende gneiss)

• Uses: primarily as a mineral specimen

Rock Type:
IgneousMetamorphic

 


ILMENITE

Mohs scale: 5.5-6

Group: Oxide

Formula: FeTiO3

Crystal Habit: Granular to massive, trigonal

Specific Gravity: 4.7

Colour: Black

Streak: Black

Did You Know?

• A hard black mineral with a metallic lustre, a major component of heavy-mineral sands, which have not yet been found in Manitoba

• A ferrous titanate, one of the most important ores of the metal titanium, found as compact crystalline masses of magmatic origin associated with gabbro-anorthosite intrusions in Manitoba's portion of the Precambrian Canadian Shield

• A significant deposit is situated in the Pipestone Lake sill, within titaniferous magnetite, in Manitoba's Cross Lake area

• Uses: in manufacture of titanium dioxide (for paint and paper pigments; plastics; rubber; ceramics; textiles; cosmetics), and in high strength-to-weight alloys for the aerospace industry

Rock Type:
IgneousMetamorphic

 


LAZULITE

Mohs scale: 5-5.5

Group: Phosphate

Formula: (Mg, Fe)Al2(PO4)2(OH)2

Crystal Habit: Monoclinic, prismatic

Specific Gravity: 3.1

Colour: Deep blue

Streak: White

Did You Know?

• A rare vitreous blue phosphate vein-mineral, found in Precambrian pegmatites and in quartz rich metamorphic rocks

• First discovered in Canada in 1879 by Dr. R. Bell, of the Geological Survey of Canada, in Precambrian quartzite near Churchill

• Can be observed at Cape Merry historic site northwest of Churchill

• Uses: a popular collector's mineral and minor gemstone

Rock Type:
Metamorphic

 


LEPIDOLITE

Mohs scale: 2.5-4

Group: Silicate

Formula: K(Li,Al,Rb)2-3(AlSi3O10)(F,OH,O)2

Crystal Habit: Tabular to prismatic, monoclinic

Specific Gravity: 2.8-2.9

Colour: Pink, purple, rose-red, violet-grey, yellowish, white, colourless

Streak: White

Did You Know?

• A purple or lilac lithium mica, usually a 'waste rock' from the mining of valuable ore minerals (pollucite, spodumene, and tantalite within the Precambrian Tanco Pegmatite at Tantalum Mining Corporation of Canada Ltd.'s mine located at Bernic Lake, east of Lac du Bonnet, Manitoba)

• Grades to muscovite

• Uses: industrial - as a heat insulator, as ornamental stone (example: bookends, plaques; must be lacquered to enhance appearance)

Rock Type:
Igneous

 


MAGNETITE

Mohs scale: 6

Group: Oxide

Formula: Fe3O4

Crystal Habit: Fine granular to massive; hexoctahedral

Specific Gravity: 5.18

Colour: Black

Streak: Black

Did You Know?

• A hard black, strongly magnetic iron oxide mineral, found typically in basic igneous rock (gabbro, anorthosite or basalt) of Precambrian age.

• An ore of iron (also called 'lodestone', which in Middle English means 'course stone' or 'leading stone'), which when suspended by a cord, and comes to rest, indicates north and south

• In Manitoba, magnetite-rich bands alternate with pale cherty or quartzitic bands in Precambrian magnetic iron formation. The best examples of this can be seen on the northwest and south shores of the largest island in Wallace Lake, a short distance to the east of Bissett, Manitoba

• Geologists are mindful of iron formations because magnetite in rock may "confuse" a compass. Luckily, today's GPS devices aren't affected by magnetic rock!

• Uses: as an aggregate in high density concrete; a toner in electro-photography; a micronutrient in fertilizers; a paint pigment; and an accent landscaping material

Rock Type:
IgneousSedimentaryMetamorphic

 


METEORITE

Mineralogy: Major mineral groups associated with meteorites are silicates, native metals, sulfides, oxides, phosphates, and carbon compounds

Did You Know?

• Space rock fragments falling to Earth contain nearly 300 known minerals, 40 of which are found only in meteorites

• Many meteorites are fragments of asteroids from the 'Asteroid Belt' situated between Mars and Jupiter

• The Elm Creek meteorite, which probably fell to earth thousands of years ago, weighed 8.2 kilograms, and is the largest meteorite and the 5th to be recovered in Manitoba (also the second-largest 'stony' meteorite found in Canada)

• Some meteorites are from manmade 'space junk' tugged to Earth by our planet's powerful gravity

Rock Type:
IgneousMetamorphic

 


MOLYBDENITE

Mohs scale: 1-1.5

Group: Sulfide

Formula: MoS2

Crystal Habit: Hexagonal

Specific Gravity: 4.62-4.73

Colour: Lead-grey

Streak: Blue-grey, greyish black

Did You Know?

• A soft black sulphide mineral that is the primary ore of molybdenum

• Associate mineral in Precambrian granitic igneous rocks, and as high temperature veins or replacements in metamorphic rocks

• Small amounts were hand-cobbed as large crystals from pegmatite in Manitoba north of Falcon Lake in the Whiteshell area during World War 1

• Important rare material for manufacture of chemical lubricants

• Other ses: as an alloy in steel, a filament in light bulbs, and in metal-working dies and furnace parts

Rock Type:
IgneousMetamorphic

 


MUSCOVITE

Mohs scale: 2-2.5

Group: Silicate

Formula: KAl2(AlSi3O10)(F,OH)2

Crystal Habit: Massive to platy; monoclinic

Specific Gravity: 2.76–2.88

Colour: Colourless,white, silvery, grey, light yellow, green, rose or brown; thick sheets may appear black

Streak: White; may 'flake' instead of streak

Did You Know?

• Most common potassium-rich rock-forming mineral of the mica family

• Abundant in Precambrian pegmatite granite in Manitoba (north shore Greer Lake and the south shore of the Winnipeg River)

• Transparent potassium-rich natural 'sheet-mica' was once used as window 'glass' and also in electric toasters

• Uses: in plastics, rubber, asphalt roofing, fireproofing and insulating materials, and lubricants; crushed muscovite is used in paint fillers and extenders to add 'glitter' to paint, ceramic glazes and cosmetics

Rock Type:
IgneousMetamorphic

 


OLIVINE

Mohs scale: 6.5-7

Group: Silicate

Formula: (Mg,Fe)2SiO4

Crystal Habit: Massive to granular crystals, orthorhombic

Specific Gravity: 3.27-4.37

Colour: Olive green, may be yellow-green to bright green, and brown-green to brown in iron-rich specimens

Streak: None

Did You Know?

• A rock-forming mineral, one of the first to crystallize from magmas that are rich in magnesium and iron

• Found in some Precambrian peridotites, gabbros and basalts in Manitoba; especially in dike-swarms near Cuthbert Lake, where the largest dike (almost 65 km in length and 0.5 km in width) may contain 15-60% olivine

• Abundant in 'ultramafic' rocks (dark coloured igneous rocks in Earth's mantle, which are rich in minerals like magnesium and iron, with a low silica content, eg. peridotite and dunite). Dunite, an igneous rock comprised almost entirely of olivine (36-42% MgO), is a commercial source of olivine. Due to metamorphism, peridotite and dunite are usually altered to serpentine and iron oxides in Manitoba

• Identified in Stony and Stony-iron meteorites

• Uses: as a gemstone (eg, a bright, transparent, yellowish green variety (known as peridot) has been valued as a gemstone for thousands of years); and in industrial applications (metallurgy, where olivine is a slag conditioner and fluxing agent in steel); magnesia fertilizer; blasting abrasive; filtration media; filler in specialty paints, asphalt and mastics

Rock Type:
Igneous

 


ORTHOCLASE (K-Feldspar)

Mohs scale: 6

Group: Silicate

Formula: KAlSi3O8

Crystal Habit: Grains elongated, tabular; monoclinic

Specific Gravity: 2.57

Colour: Colourless to green, grey-yellow, white, and pink

Streak: White

Did You Know?

• A potassic feldspar that is a major mineral in most light-coloured Precambian granitoid rocks, such as granite and rhyolite, in Manitoba

• Often forms large crystals in pegmatite (notably, at Tantalum Mining Corporation of Canada Ltd.'s Tanco mine at Bernic Lake in southeast Manitoba)

• Uses: ceramics, porcelains, mild abrasives (eg. Bon Ami Powder Cleanser®), jewelry and gemstones

Rock Type:
IgneousSedimentaryMetamorphic

 


PEGMATITE

Mineralogy: Typically feldspar and quartz, with minor phosphate, oxide or other silicate minerals

Did You Know?

• Very coarse-grained (rough-feeling) igneous rocks that crystallize (produce crystals) during the latest stages of cooling of large bodies of granitic magma (molten rock)

• Many pegmatites rich with rare elements, also contain unusual minerals (about 75 mineral species have been reported from the Tanco pegmatite)

• World-famous Tanco pegmatite, located at Manitoba's Bernic Lake, is one of the largest and most studied examples on Earth

• Uses: an important source of rare metals, some gemstones/jewels; also as ornamental stone (stone used in decoration)

Rock Type:
Igneous

 


PENTLANDITE

Mohs scale: 3.5-4

Group: Sulfide

Formula: (Fe,Ni)9S8

Crystal Habit: Massive, granular, isometric

Specific Gravity: 4.6-5

Colour: Yellow-brown

Streak: Light bronze-brown, green-black

Did You Know?

• A non-magnetic yellow bronze iron nickel sulphide occurring in massive or granular aggregates, found in Precambrian greenstone belts in Manitoba

• The most important global source of nickel, associated with sulfide minerals such as pyrrhotite and chalcopyrite

• First mined in 1953 in northern Manitoba during development of the Sherritt Gordon Mines Limited's "A" and "EL" nickel-copper mines at Lynn Lake, where nickel production continued until 1976

• Mined today by Vale Canada Ltd. at its Thompson and Birchtree mines in Manitoba (smelting and refining phased out at Thompson in 2015)

• In 2014, Manitoba produced 12.2% of Canada's nickel (26 667 tonnes worth $497 223 000) from the Thompson and Birchtree mines owned by Vale Canada Ltd., near Thompson

• Uses: in steel and steel alloys

Rock Type:
Igneous

 


POLLUCITE

Mohs scale: 6.5

Group: Silicate (Feldspathoid group)

Formula: (Cs,Na)2(Al2Si4O12)2H2O

Crystal Habit: Isometric

Specific Gravity: 2.9

Colour: Colourless, also white, grey, pink, blue, violet

Streak: White

Did You Know?

• A hydrous cesium aluminum silicate mined for cesium ore within the Precambrian Tanco Pegmatite in southeast Manitoba at Bernic Lake, near Lac du Bonnet

• Bernic Lake mine produced 100% of Canada's cesium (2012 data)

• Tantalum Mining Corporation of Canada Ltd. (Tanco) contains about 82% of the world's known pollucite reserves

• Uses: Cesium formate (an environmentally-friendly heavy drilling fluid, 3X the weight of water is leased by Tanco to drilling companies who recover it after use in North Sea oil wells, and return it to Tanco for recycling ); cesium can also be used to generate slow, but continuous thrust (utilizing relatively small quantities of fuel) in ion-propelled rockets in outer space; applications in photoelectric cells, photomultipler and vacuum tubes, infrared lamps, scintillation counters, magnetometers, pharmaceuticals and in microanalysis; clear material from Maine (extremely scarce) has been cut into gemstones, sought by collectors because of their rarity

Rock Type:
Igneous

 


PYRITE

Mohs scale: 6-6.5

Group: Sulfide

Formula: FeS2

Crystal Habit: Isometric, diploidal

Specific Gravity: 5.02

Colour: Brass-yellow

Streak: Green-black to brown-black

Did You Know?

• Abundant in Manitoba and found in Precambrian copper-zinc, nickel-copper and gold ore suites, as well as in small quantities in Paleozoic carbonate and Mesozoic shale rocks

• Nicknamed "Fool's Gold" because it acquires a deeper yellow or 'golden' tone when it tarnishes upon exposure to air

• Is often found in the same localities as real gold

• The name 'pyrite' comes from a Greek word 'pyr' (fire)

• Weathered surfaces of pyrite occurrences are normally altered to rusty brown limonitic oxidized cappings, known as 'gossan' which is sought by prospectors as it may indicate the presence of gold or other valuable metals

• Uses: as an ore of gold; sometimes as a gemstone; in the past used to produce sulphuric acid

Rock Type:
IgneousSedimentaryMetamorphic

 


PYRRHOTITE

Mohs scale: 4

Group: Sulfide

Formula: Fe1-xS

Crystal Habit: Monoclinic prismatic

Specific Gravity: 4.58-4.65

Colour: Bronze-yellow, brown-bronze, red-bronze

Streak: Dark grey-black

Did You Know?

• Abundant in Manitoba where it is a common sulfide mineral in nickel and platinum group metal (PGM) deposits, and most common magnetic mineral next to magnetite, found in Precambrian greenstone belts

• Mined in association with pentlandite, and found with pentlandite in basic igneous rocks

• Uses: no specific applications, but in the past pyrrhotite was used for the production of sulphuric acid

Rock Type:
IgneousMetamorphic

 


QUARTZ

Mohs scale: 7

Group: Silicate

Formula: SiO2

Crystal Habit: Fine-grained to microcrystalline, massive; hexagonal

Specific Gravity: 2.65

Colour: Typically colourless, but may occur in various colours

Streak: Colourless to white, harder than streak plate

Did You Know?

• Rock-forming silica mineral, found abundantly in siliceous rocks (such as Precambrian granite), sedimentary rocks (such as sandstone), and metamorphic rocks (such as quartzite and gneiss)

• Second most abundant mineral (approximately 12%) in Earth's crust

• Best formed crystals are formed in geodes, which are rock-cavities lined with inward-projecting crystals

• Clear, colourless quartz crystals were much used in past centuries as gemstones, and massive transparent quartz (rock crystal) was carved and polished in ancient Greece as ornamental bowls and vases

• A purple-coloured variety of quartz known as amethyst is sometimes used as a gemstone

• Produced in limited amounts by Tantalum Mining Corporation of Canada Ltd. at Tanco Mine at Bernic Lake, Manitoba

• From 1956 to 1990, quartz present in high purity and friable quartz sandstone (95-96% SiO2) was quarried and washed (up to 100 000 tonnes per year) on Black Island of Lake Winnipeg:

- The Ordovician (550 million year old) Winnipeg Formation sand was transported by barge to Selkirk, Manitoba

- At Selkirk, the sand was processed (99.558% SiO2) for use in glass manufacture, foundry sand, filter sand, frac sand and blasting sand

- Much of the production was shipped to Redcliff, Alberta where it was made into glass containers

• Other uses: abrasives, metallurgical flux, hydraulics, sand slurries, high quality quartz (min. 99.8% SiO2) used for eyeglasses and optical equipment, manufacture of silicon carbide and cement, as a filler material in tile, asbestos pipe, concrete and bricks

Rock Type:
IgneousSedimentaryMetamorphic

 


SCHEELITE

Mohs scale: 4.5-5

Group: Oxide (Tungstate group)

Formula: CaWO4

Crystal Habit: Tetragonal, massive, granular

Specific Gravity: 5.9-6.1

Colour: Colourless, white, grey, brown, pale yellow, yellow-orange, pale shades of orange, red, green

Streak: White

Did You Know?

• Calcium tungstate, an ore of tungsten, a by-product of gold production

• Small amounts of scheelite (tungsten ore) were extracted from Precambrian deposits situated north of Falcon Lake in the Whiteshell area of Manitoba in 1918, and east of Wekusko Lake during World War 1. The tungsten was used as an alloy-metal for guns, projectiles and armour-plating

• Because of its good electrical conductivity, once commonly used in incandescent lighting. Now being replaced by more efficient mini-fluorescent lights and LEDs

• Scheelite is fluorescent under ultra-violet light, showing colour effects from blue to white and yellow. Portable black light devices have been used in the field to explore for scheelite

• Over half of the tungsten consumption in North America is as carbides, chemically combining metallic tungsten powder with finely divided carbon. The resultant compound is then used to make carbide cutting tools and wear resistant parts, such carbide-tipped drill bits used for drilling rock

• Other uses: as a gemstone because some colourless gems sparkle, almost like diamonds, owing to their considerable light dispersion effects. It is also used to make high-tungsten alloys used in jet and rocket engines, turbine blades and combustion-chamber liners

Rock Type:
IgneousMetamorphic

 


SERPENTINE

Mohs scale: 3-5

Group: Silicate

Formula: Mg3Si2O5(OH)4

Crystal Habit: Monoclinic

Specific Gravity: 2.5-2.6

Colour: Various shades of green

Streak: White

Did You Know?

• Serpentine does not form crystals, but occurs in massive, granular or fibrous forms. In Manitoba, it occurs principally as the main constituent of the Precambrian rock serpentinite, some of which may show colour banding and mottling

• Found in rocks formed by 'serpentinization' (hydration and metamorphic transformation of olivine in ultramafic rocks from the Earth's mantle)

• Abundant in Manitoba, serpentine is well known in the Thompson Nickel Belt area and the Fox River sill

• About 1950, Manitoba Marble Quarries Limited quarried serpentinite, 550 metres east of Clangula Lake near Wanipigow, as a source of ornamental stone. However, the friable nature of the rock reduced its value as an ornamental stone

• Chrysotile (the best known form of serpentine) is the most important source of commercial asbestos

• Uses: Ornamental stone, jewellery and ornaments, thermal conductivity and as an industrial mineral

Rock Type:
Metamorphic

 


SIDERITE

Mohs scale: 4-4.5

Group: Carbonate

Formula: FeCO3

Crystal Habit: Hexagonal

Specific Gravity: 3.96

Colour: Yellow-brown to grey-brown, tan, grey, brown, green, red, black, or sometimes nearly colourless. Tarnishes 'iridescent' (appears to change colours when observed at different angles and under different light)

Streak: White

Did You Know?

• Important brown, buff or reddish iron carbonate ore of iron in Europe

• Named from Greek word for iron, 'sideros'

• Found in iron-rich Phanerozoic sedimentary rocks, shale beds, coal seams

• Forms crystals in hydrothermal veins and in banded Precambrian iron formation

• Effervesces with hot hydrochloric acid

• Uses: popular collector's mineral, may be used as a brown pigment

Rock Type:
Sedimentary Metamorphic

 


SPHALERITE

Mohs scale: 3.5-4

Group: Sulfide

Formula: (Zn,Fe)S

Crystal Habit: Isometric

Specific Gravity: 3.9-4.1

Colour: Yellow, brown, black, red, (colourless when pure)

Streak: White to yellow-brown (sulfur odour may be present)

Did You Know?

• Primary ore of zinc, found in Precambrian greenstone belts in Manitoba

• First produced in 1930 from ore mined beneath the town of Flin Flon by Hudson Bay Mining and Smelting Co., Limited (now Hudbay Minerals Inc.)

• Hudbay has produced sphalerite from its mines in the world famous Flin Flon-Snow Lake greenstone belt for over 80 years

• A major use of zinc is the galvanized coating applied to steel to prevent corrosion by atmosphere, water and soil, thereby extending the life of the steel found in buildings, automobiles, ships and steel structures of every kind

• The U.S. penny is 98% zinc with a copper coating

• In 2014, Manitoba produced 23.6% of Canada's zinc (76 182 tonnes worth $182 076 000) from mines owned by Hudbay Minerals Inc. in the Flin Flon-Snow Lake greenstone belt

• Although "spharlerite/galena" has been known to occur in igneous and metamorphic rocks in Manitoba since the early 1900s, it was first discovered in sedimentary rock (dolomite of the Cedar Lake Formation within the Silurian Interlake Group) in 2004 in the north basin of Lake Winnipegosis, near the northeast end of Pemmican Island

• Other uses: natural insect repellent and sunscreen; necessary for growth, reproduction and good health (boosting the immune system, helping cells to grow, regulating appetite and healing wounds); sphalerite crystals may be used as faceted gemstones

Rock Type:
IgneousSedimentaryMetamorphic

 


SPODUMENE

Mohs scale: 6.5-7

Group: Silicate

Formula: LiAlSi2O6

Crystal Habit: Prismatic crystals, elongated, flattened; monoclinic (low temperature) tetragonal (high temperature)

Specific Gravity: 3.15-3.2

Colour: White, grey, yellow, green, blue, lilac, pink, brown; (sometimes 'pleochroic' – appears to change colours when observed at different angles or under different light)

Streak: White, colourless

Did You Know?

• A comparatively rare, clinopyroxene (sub group mineral), and the most important of the lithium minerals

• Once mined in a high-grade spodumene zone (4.5 million tonnes) within the Precambrian Tanco Pegmatite by Tantalum Mining Corporation of Canada Ltd. at Bernic Lake, to produce raw lithium-rich ceramic material that went into Corelle™ dinnerware

• The Tanco spodumene occurs as white lath-shaped crystals up to 1.5 metres in length; or in tabular aggregates (intergrown with quartz) up to 2 metres across. However, in South Dakota, large well-shaped crystals with record lengths of 12.8 metres have been found

• Uses: manufacture of special types of ceramic, glass and enamelware; welding and brazing fluxes; and potential new opportunity exists for Manitoba spodumene to be used as a gemstone

Rock Type:
Igneous

 


STAUROLITE

Mohs scale: 7-7.5

Group: Silicate

Formula: (Fe,Mg)2Al9O6(SiO4)4(O,OH)2

Crystal Habit: Monoclinic, prismatic

Specific Gravity: 3.65-3.75

Colour: Brown, red-brown, yellow-brown, brown-black, black, dark grey

Streak: White to grey

Did You Know?

• Metamorphic hydroxyl-bearing iron aluminum silicate rock-forming mineral of sedimentary (argillaceous) origin, often found with Precambrian gneiss and schist

• Associated with garnet, kyanite and muscovite

• Commonly forms six-sided twinned crystals, intersecting at 60 or 90 degrees, giving it the name "stauros" (Greek word for "cross")

• In the past, have been sought as lucky charms, called fairy-stones or fairy crosses

• Principal staurolite occurrences in Manitoba are in the Snow Lake Region, east of Wekusko Lake and west and northwest of File Lake. Good dark brown staurolite crystals are abundant, 3 km east of Snow Lake, where Provincial Road 392 crosses Snow Creek

• Uses: in geologic field work to assess metamorphic history of rock; loose-grain blasting abrasive (metal cleaning, sandblasting buildings); paint primer filler, also as gemstones in Switzerland

Rock Type:
Metamorphic

 


SYLVITE (Carnalite)

Mohs scale: 2

Group: Halide

Formula: KCl

Crystal Habit: Isometric

Specific Gravity: 1.99

Colour: Colourless, white, blue, yellow, grey (or red, due to presence of hematite)

Streak: White

Did You Know?

• Sylvite, carnallite and kainite are potash commercial minerals that often intercrystallized with halite

• An 'evaporite' mineral, (occurs by evaporation in inland lakes or oceans)

• Commonly found as salt beds in sedimentary deposits

• Found in Devonian Prairie Evaporite potash beds in the subsurface of Manitoba from the Saskatchewan boundary to the Assiniboine River (from Harrowby in the north to McAuley in the south)

• Official mineral of Manitoba's closest western 'neighbour', the province of Saskatchewan

• Uses: salt substitute; also a major source (95%) of potassium or potash in agricultural fertilizer products; drilling mud additive

Rock Type:
Sedimentary

 


TALC

Mohs scale: 1

Group: Silicate

Formula: Mg3Si4O10(OH)2

Crystal Habit: Foliated to fibrous, monoclinic

Specific Gravity: 2.7-2.8

Colour: Colourless, green, white, grey, brown

Streak: White to pale green

Did You Know?

• Extremely soft, nonabrasive, inert, hydrated magnesium silicate mineral, found in several Manitoba Precambrian greenstone belts — near the Lynn Lake and Flin Flon mines and near Iskwasum Lake; and in ultramafic bodies at Embury Lake

• Formed as an alteration product of some magnesium-rich minerals, including pyroxene, serpentine and dolomite

• Major constituent of soapstone, with fibre-like texture and 'oily or greasy' feel. Soapstone is the massive and impure talc-rock that can be quarried, sawn off in blocks, and used for carving

• Uses: talcum (or baby) powder, paper, plastics, ceramics, paint, roofing materials, lubricants, filler in medical tablets and pastes, insecticide and fungicides

Rock Type:
Metamorphic

 


TANTALITE

Mohs scale: 6

Group: Oxide

Formula: (Fe,Mn)Ta2O6

Crystal Habit: Orthorhombic

Specific Gravity: 5.2-7.9

Colour: Dark black, iron-black to dark brown, red-brown

Streak: Brown-red to black

Did You Know?

• Tantalite (tantalum ore) was once mined from the Precambrian Tanco Pegmatite by the Tantalum Mining Corporation of Canada Ltd. at Bernic Lake (SE Manitoba). The mine was one of the world’s major producers of tantalite, which was shipped to the United States for extraction of the tantalum

• Often occurs as tiny black (manganese-rich) skeletal specks in white granitic pegmatite; particularly those containing marked amounts of albite, lithium silicate, and lithium-magnesium-iron phosphate

• Tantalum ore can be extracted from tantalite and from its end-member 'columbium' (sometimes referred to together as 'coltan')

• Uses: electronic devices (cell phones, tablets, etc.,) satellites in Earth's orbit, (tantalum capacitors). Also, in the making of sheet, tube and other mill products mainly for the chemical industry; cutting tools; additives to alloys; tantalum salts and oxides, in the tantalum carbide industry

Rock Type:
Igneous

 


TETRAHEDRITE

Mohs scale: 3-4.5

Group: Sulfosalt

Formula: Cu12Sb4S13

Crystal Habit: Cubic, hextetrahedral

Specific Gravity: 4.6-5.1

Colour: Steel-grey to iron-grey

Streak: Black, brown to dark red

Did You Know?

• A greyish black ore of copper and silver, occasionally found in copper-zinc ores, as cubic or tetrahedral crystals, or can be massive or granular

• It is essentially a sulphantimonide of copper (but iron, zinc and silver may be present in variable proportions) that is common in hydrothermal veins

• Silver, contained in a variety of silver-bearing minerals (such as, tetrahedrite and argentite) is produced as a minor by-product of Precambrian gold (Kiski mine), copper-zinc (Flin Flon, Chisel Lake and Centennial mines) and nickel-copper mining in Manitoba

• Uses of copper: building construction; power generation and transmission; house and office electrical wiring; water pipes; heating and cooling systems; telecommunications; electronic product manufacturing; production of industrial machinery and vehicles

• Uses of silver: The primary use of silver is in the electronics industry due to its unsurpassed thermal and electrical conductivity. Historically, silver has been used in coins, silverware, and jewelry. It is used in medicine and consumer products because of its antimicrobial and non-toxic qualitites. It is also used to make mirrors and wire, and in film photography

Rock Type:
Metamorphic

 


TOURMALINE (Schorl)

Mohs scale: 7-7.5

Group: Silicate

Formula: (Na(Fe,Mn)3Al6Si6O18(BO3)3(OH,F)4

Crystal Habit: Hexagonal

Specific Gravity: 3-3.25

Colour: Black

Streak: Colourless, grey

Did You Know?

• A complex silicate of boron and aluminum, with an extremely complex chemical formula, found in Precambrian pegmatite in Manitoba

• Tourmaline has the property of pyroelectricity (becoming electrically charged, when heated); specimens left in sunlight may become dust covered due to its electrical attraction

• Tourmaline also has the property of piezoelectricity (developing an electric charge when thinly sliced and compressed). This property makes it suitable for use in high-pressure gauges

• Tourmaline was found in Manitoba at Chisel Lake, Nor Acme, Rex, Bingo, Moosehorn, Kiski, and McCafferty mines near Snow Lake

• Schlorlite, a common black iron-rich tourmaline is well exposed in coarse-grained pegmatite dike that forms a cliff on the south shore of the bay at Manitoba's Pickerel Narrows on Granville Lake

• Uses: in various forms of electronics and technology; popular as a semi-precious gemstone because of its hardness, lustre, crystalline form, virtual lack of cleavage and remarkable range of colours

Rock Type:
IgneousMetamorphic

 


TYNDALL® STONE

Mineralogy: Dolomite and calcite

Did You Know?

• Also called "tapestry" stone

• Mottled dolomitic limestone first found (within the Selkirk Member of the Red River Formation) near Garson, Manitoba in the late 1800s by a farmer digging a shallow water well

• May contain Late Ordovician (445 million years old) marine fossils such as: cephalopods, corals sponges, gastropods, crinoids, trilobites, brachiopods, clams and algae

• Underlies much of southwest Manitoba (greater depths towards southwest corner of the Province)

• First large Manitoba quarry opened by William Garson in 1898, and operated by Gillis Quarries Limited since 1915

• Tyndall® stone was described by the late author (and former University of Manitoba professor) Carol Shields in her Pulitzer Prize winning novel, The Stone Diaries

• Uses: found in the architecture the Parliament Buildings in Ottawa; the Canadian Museum of Civilization in Gatineau; the Provincial Legislative Building in Manitoba; and the Empress Hotel in Victoria, to name a few

Rock Type:
Sedimentary

 






 

SELECTED REFERENCES:

Bamburak, J.D. 1998: Industrial minerals in Manitoba; Industrial minerals in Canada, Vancouver, British Columbia, October 21–23, 1998, Focus on industrial minerals 1998: extended abstracts, p. 73–78.

Harben, Peter W. 2003: The industrial minerals handybook; a guide to markets, specifications & prices -- London, UK : Industrial Minerals Division, Metal Bulletin Plc.

Phillips, K.A. and Carruthers, B. 1976: Common rocks in Manitoba; Manitoba Mines, Resources and Environmental Management; Mineral Resources Division, Mineral Education Series 76-1, 38 p.

Phillips, K.A. 1978: Minerals of Manitoba: Volume I: Non-metallic and pegmatitic; Manitoba Mines, Resources and Environmental Management; Mineral Resources Division, MRD Educational Series 78/1, 115 p.

Phillips, K.A. 1979: Minerals of Manitoba: Volume II: Metallic minerals; Manitoba Mines, Natural Resources and Environment; Mineral Resources Division, MRD Educational Series 78/2, 84 p.

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