Ch 3 Minerals Worlds largest diamond mine

Layers of the Earth Crust (8 to 32 km) Mantle (2900 km) Liquid Core(2250 km) Solid Core (1300 km)

Core 1. Solid Inner Core: Made of solid Nickel and Iron Made of solid Nickel and Iron Under great pressure - resulting in a solid form. Under great pressure - resulting in a solid form. Iron causes the Earth to be magnetic Iron causes the Earth to be magnetic 5000 degrees Celsius 5000 degrees Celsius 2. Liquid Outer Core Made of liquid Nickel and Iron 2200 degrees Celsius

Mantle Molten, liquid rock (Magma) Molten, liquid rock (Magma) Makes up about 80% of Earth’s volume Makes up about 80% of Earth’s volume Ranges from 870 to 2200 degrees Celsius Ranges from 870 to 2200 degrees Celsius Crust and Mantle divided by the Moho Boundary Crust and Mantle divided by the Moho Boundary

Crust Very thin, solid layer of rock Very thin, solid layer of rock Made of mostly Silicon & Oxygen (75%) Made of mostly Silicon & Oxygen (75%)

What are Minerals? Naturally occurring – Naturally occurring – not man-made, in the earth Inorganic – Inorganic – doesn’t come from living things Always a solid – Always a solid – has volume and shape

Definite chemical composition – Definite chemical composition – made of a single pure substance or element Crystalline form – Crystalline form – flat sides, sharp edges & corners

Formation & Composition As hot magma cools, the minerals will crystallize. As hot magma cools, the minerals will crystallize. If the magma cools very slowly it forms large crystals. If it cools very quickly it forms tiny to microscopic crystals. If the magma cools very slowly it forms large crystals. If it cools very quickly it forms tiny to microscopic crystals.

Some mineral crystals will form compounds dissolved in liquids. Minerals will be left behind when the liquid evaporates. Some mineral crystals will form compounds dissolved in liquids. Minerals will be left behind when the liquid evaporates.

The eight most common elements in the crust form a large number of the known minerals. The eight most common elements in the crust form a large number of the known minerals. (O, Si, Al, Fe, Ca, Na, K, & Mg) The compound formed by Silicon & Oxygen is known as Silicate. The compound formed by Silicon & Oxygen is known as Silicate. Mineral Identification The identification of a mineral is based on its physical properties The identification of a mineral is based on its physical properties

1.Color Some minerals have characteristic colorsSome minerals have characteristic colors Some minerals can come in several different color varietiesSome minerals can come in several different color varieties EX: Quartz & Corundum Some of the colors can change due to temperature, pollution, or radiation.

2.Luster The way a mineral reflects light off its surface. The way a mineral reflects light off its surface. 2 types 2 types A.Metallic – very shiny, looks like a metal B.Non-metallic - Glassy – shiny, transparent, translucent

Earthy - clay-like, dull Earthy - clay-like, dull Pearly: pearl-like Pearly: pearl-like

3.Hardness The ability for a mineral to resist being scratched. The ability for a mineral to resist being scratched. Mohs Hardness Scale A list of ten minerals ranked according to hardness. A list of ten minerals ranked according to hardness. 1= softest (talc) 10=hardest (diamond)

1. Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6. Feldspar 7. Quartz8. Topaz 9. Corundum 10. Diamond

A mineral that is higher on the scale will scratch the mineral that is lower. A mineral that is higher on the scale will scratch the mineral that is lower. Other common items have been given ratings on the scale for identification purposes. Other common items have been given ratings on the scale for identification purposes. EX: Fingernail, Penny, File, Glass EX: Fingernail, Penny, File, Glass

4.Streak The color of the powder scraped off a mineral when rubbed against a rough surface (streak plate.) The color of the powder scraped off a mineral when rubbed against a rough surface (streak plate.) Very useful property for showing the TRUE color. Very useful property for showing the TRUE color. Same color always, no matter what the variation Same color always, no matter what the variation

5.Breakage 2 types – a. Cleavage - breaks in smooth, definite surfaces Same every timeSame every time b. Fracture - breaks in rough or jagged surfaces

6.Crystal Form Geometric crystals with flat surfaces and definite edgesGeometric crystals with flat surfaces and definite edges CubicCubic HexagonalHexagonal TetragonalTetragonal OrthorhombicOrthorhombic MonoclinicMonoclinic TriclinicTriclinic Different from cleavageDifferent from cleavage

7.Other Properties 1. Reaction to Acid - some minerals will bubble in acid 2. Magnetism - some special minerals will be magnetic will be magnetic 3. Smell - some will have distinct odors 4. Taste - some have a distinct taste Sulfur Halite Calcite

Mineral Groups 1. Silicates Most common mineral familyMost common mineral family Silicon-oxygen tetrahedron (SiO 4 ) along with additional elements.Silicon-oxygen tetrahedron (SiO 4 ) along with additional elements. Joined together into chains, sheets, or 3-demensional networks.Joined together into chains, sheets, or 3-demensional networks. EXAMPLES: Feldspars, Quartz, Micas

2. Carbonates Carbonates are used in cement & lime.Carbonates are used in cement & lime. Made of Carbonate (CO 3 ) with other elements.Made of Carbonate (CO 3 ) with other elements. EXAMPLES: Calcite & Dolomite 3. Halides Used in steel making, fertilizer, & saltUsed in steel making, fertilizer, & salt EXAMPLES: Halite & Fluorite

4. Sulfates Used in plaster.Used in plaster. Made of Sulfate (SO 4 ) with other elements.Made of Sulfate (SO 4 ) with other elements. EXAMPLE: Gypsum 5. Oxides Have Oxygen as a major component.Have Oxygen as a major component. EXAMPLES: Hematite, Magnetite, Corundum, & Ice

6. Native Elements Minerals of great economic value that are pure elements.Minerals of great economic value that are pure elements. EXAMPLES: Gold, Silver, Diamond (C), Sulfur, Graphite (C), Copper, Platinum

Uses for Minerals 1. Ores Minerals or combinations of minerals from which metals and nonmetals can be removed in usable amounts. Minerals or combinations of minerals from which metals and nonmetals can be removed in usable amounts. Examples: Cinnabar (Mercury), Bauxite (Aluminum), Hematite (Iron)

Smelting- when an ore is heated so that a metal can be separated from it.Smelting- when an ore is heated so that a metal can be separated from it. Alloys- when pure metals are combined to form other metallic substances. (Steel & Brass)Alloys- when pure metals are combined to form other metallic substances. (Steel & Brass)

2. Gemstones Minerals that are hard, beautiful, and durable.Minerals that are hard, beautiful, and durable. They are substances that can be cut & polished for jewelry & decoration.They are substances that can be cut & polished for jewelry & decoration.

a. Precious Stones The rarest & most valuable.The rarest & most valuable. Ex: Diamonds, Rubies, Opals, Sapphires, & Emeralds

b. Semiprecious Stones The other gemstonesThe other gemstones Ex: Amethysts, Zircons, Garnets, Turquoises, Jades, & more

c. Non-Mineral Gemstones Come from living thingsCome from living things Ex:Amber, Pearls, & Coral