Colour Brassy yellow/green

Hardness 3.5-4

Streak Green-black

Magnetic No

Conductive Yes

Lustre Metallic

Distinguishing Characteristics

Conductive

Use Chalcopyrite is the primary ore of copper. Copper is used in electrical wires, plumbing pipes, coins, and kitchen appliances-just to name a few.

CHALCOPYRITE

MICA

Colour Dark brown (biotite), colourless (muscovite)

Hardness 2.5-3

Streak White

Magnetic No

Conductive No

Lustre Pearly, vitreous (glassy)

Distinguishing Characteristics

Sheets flake off in layers

Use Mica is used as an industrial heat insulator. Scrap and ground mica is used in wall paper, fancy paint, ornamental tile, roofing and lubricating oils. Makeup also contains tiny flecks of mica to obtain a sparkling effect.

CALCITE (Calcium Carbonate)

Colour Light bronze-yellow

Hardness 3

Streak White or grey

Magnetic No

Conductive No

Lustre Vitreous (dull)

Distinguishing Characteristics

Bubbles or fizzes with dilute acid (HCl)

Use Calcite is used in mortar, cements and the production of lime. It is used in fertilizers, toothpaste and other chemicals. It is also used in the glass industry as well as having other optical properties.

GYPSUM

Colour White, colourless or grey

Hardness 2

Streak White

Magnetic No

Conductive No

Lustre Vitreous (glassy) or pearly

Distinguishing Characteristics

Soft, but not as soft as talc

Use Gypsum is used to make chalk, drywall, plaster, cement, caulking and paints.

SPHALERITE (Zinc)

Colour Yellow to brown, black-yellow

Hardness 3.5-4

Streak Light yellow to brown

Magnetic No

Conductive No

Lustre Resinous to nearly metallic (dull)

Distinguishing Characteristics

Good cleavage and lustre

Use Zinc is used for coating iron and steel to prevent rusting or corrosion. The process of improving the corrosion resistance of steels is called galvanization. Zinc is also used in alkaline batteries, zinc oxide, calamine lotion, nutritional supplements and in water purification technology.

HALITE

Colour Colourless or white

Hardness 2.5

Streak White

Magnetic No

Conductive No

Lustre Vitreous (glassy)

Distinguishing Characteristics

Tastes salty, clear and colourless. Halite can be easily identified by its cubic crystal form and breaks (or cleave) at right angles.

Use Halite is used as a road salt and table salt. It is also used in the manufacture of glass, fire extinguishers, paint, plastics, synthetic rubbers and cosmetics.

TALC

Colour Green, grey to white or yellow

Hardness 1

Streak White

Magnetic No

Conductive No

Lustre Pearly to greasy; vitreous (glassy)

Distinguishing Characteristics

Softness

Use Talc is used in cosmetics, beauty products, as filler for paints, rubber and insecticides.

LIMESTONE

Rock Type Sedimentary rock

Composition Mostly the mineral calcite

Distinguishing Characteristics

Whitish-grey with a chalky texture. There are no visible fossils in this sample.

Use Limestone is used in the manufacture of Portland cement and paper production. It is also used in the agricultural industry and as a dimension stone.

Pure limestone is used as flux in the steel making process and is used in the production of glass. Other applications include sugar refining and acid lake treatment.

HEMATITE

Colour Steel-grey or black to red-brown

Hardness 5-6

Streak Red or red-brown

Magnetic Weakly magnetic

Conductive No

Lustre Metallic (dull) to earthy

Distinguishing Characteristics

Red-brown streak

Use Hematite is the primary ore of iron. Iron is used in the manufacture of steel and pig iron. It is also used in wrought iron, cast iron, nutritional supplements, and blueprints.