Galena Chemical formula Pb S Lead Sulfide One

Galena • Chemical formula: Pb. S (Lead Sulfide) • One of the most attractive of all the minerals • Contains over 86% Lead • Luster: metallic • Mohs Scale: 2. 5 -2. 75 • Occurrence: uncommon • Galena is the world's primary source of lead, which is used to make … » lead-acid batteries » lead-lined tanks that store corrosive liquids » lead shields that protect against X-ray and gamma radiation » lead + tin alloy is called solder and used to join electrical components » lead crystal is a decorative glass » lead bullets used in low velocity weapons

Magnetite • Chemical Formula: Fe 3 O 4 • the best ore of iron, containing over 72% iron • strongly attracted to a magnet • magnetite that acts like a magnet is called “Lodestone” and was used by ancient people as a compass • Mohs scale: 5 -6 • Luster: metallic • Occurrence: common • Uses: iron is extracted to make steel, or rock is ground up and used as an abrasive in “emery” files or as an ingredient in fertilizer

Malachite • Chemical Formula: Cu 2 CO 3(OH)2 • Copper carbonate mineral • Contains about 57% copper • Luster: dull in massive forms and silky as crystals • Mohs Scale: 3. 5 - 4 • Occurrence: uncommon • Uses: polished stones are used in jewelry

Hematite • most common of the iron ores • contains 60 - 70% iron • has red or reddish streaks and is referred to as BIF (banded iron formation) • Chemical formula: Fe 2 O 3 • Luster: metallic • Occurrence: common • Mohs scale: 5. 5 - 6. 5 • the iron extracted form the ore is used to make steel

Gypsum • Most frequently found in sedimentary rocks, like limestone • Derived from the Greek work for, “chalk” or “plaster” • Chemical formula: Ca. SO 4· 2 H 2 O (hydrous calcium sulfate) • Luster: pearly • Mohs scale: 1. 5 -2 (easily scratched with fingernail) • Occurrence: common in L. P. • Mainly use in drywall, which is 1/4 inch of gypsum between two sheets of paper, also used in cement, plaster of Paris and soil conditioning

Halite • Chemical formula: Na. Cl • Also known as rock salt • Occurs where ancients seas slowly evaporated • Mohs scale: 2 - 2. 5 • Luster: vitreous • Occurrence: common • Uses: managing ice, putting salt on ice will cause it to melt

Talc • Chemical Formula: Mg 3 Si 4 O 10(OH)2 • Not soluble in water • Soap stone is a metamorphic rock composed mostly of talc • Mohs Scale: 1 (the defining mineral) • Luster: waxy or pearly • Occurrence: uncommon in MI • Uses: science lab counter and electrical switchboards because of its resistance to heat, electricity and acids, also used as an astringent in “baby

Limonite • Chemical Formula: Fe. O(OH) • n. H 2 O (called iron oxide hydroxide) • Not a true mineral, but a rock that is mined for its iron • Forms as a result of iron minerals weathering • Some found just below the surface of marshlands and is called “bog ore” • Mohs scale: 4 - 5. 5 • Luster: earthy • Occurrence: very common • Uses: mined for its iron content, which is used to make steel

Shale • Sedimentary rock • Composed of mud that is a mixture of fine grain clay and silt • Cleavage along a parallel planes • Shale that is subjected to the heat and pressure of metamorphism becomes slate • Mohs scale: less than 5 • Occurrence: Common • Uses: some shale is so rich in fossils that it can be processed for coal and oil

Chalcocite • • • Chemical Formula: Cu 2 S Important ore of copper Mohs scale: 2. 5 -3 Luster: metallic Occurrence: common Uses: the copper in the ore is extracted and used to make electrical wiring, plumbing and roofing material

Pyrite • • Chemical Formula: Fe. S 2 (iron sulfide) “Fool’s Gold” Most common of the sulfide minerals Abundant in mining dumps where it weathers and releases its sulfur, which chemically reacts with oxygen and water to form sulfuric acid, resulting in “acid mine drainage” Mohs Scale: 6 - 6. 5 Luster: metallic Occurrence: common Uses: production of sulfur dioxide which is then used to make paper

Quartz • • Chemical formula: Si. O 2 (silicon dioxide) Second most abundant mineral on the planet (feldspar is the most abundant), because it is a component of so many rocks Pure quartz is also called “rock crystal” There are many different varieties and colors of quartz Mohs scale: 7 Luster: vitreous Occurrence: very common Uses – component of sandpaper and files, – an electric circuit in clocks and computers, – decorative glass – quartz sand is used on beaches, baseball diamonds and golf courses

Calcite • • • Chemical formula: Ca. CO 3 (calcium carbonate) Calcite crystals are hexagonal (6 -sided) prisms Commonly found in rocks, like limestone and marble Crystals of calcite have an optical property called bifrigence or double refraction, draw one line on your paper, place the calcite crystal on it and you will see two lines Crystals effervesce (bubbles) in acids, like vinegar When carefully broken the crystal forms a rhombohedron, a shape that looks like a leaning cube Mohs scale: 3 (defining mineral) Luster: vitreous to pearly Occurrence: Very Common Uses: calcite is the primary mineral in limestone and marble which are used as building stones and flooring material, calcite is used to neutralize acids, so it is found in antacid tablets

Limestone • Sedimentary rock • Consist mostly of calcite (calcium carbonate), clay and quartz • World’s largest limestone quarry is in Rogers City Michigan • Partially soluble, especially in acids and therefore forms eroded landforms Arch Rock on Mackinaw Island • Occurrence: very common • Uses: used as a building stone and in the manufacture of lime, carbon dioxide, and cement.