Ch 3 MineralsCh 3 Minerals

Worlds largest diamond mine

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

CoreCore1. 1. Solid Inner Core:Solid Inner Core: • Made of solid Nickel and IronMade of solid Nickel and Iron• Under great pressure -Under great pressure -

resulting in a solid form.resulting in a solid form.• Iron causes the Earth to be Iron causes the Earth to be

magneticmagnetic• 5000 degrees Celsius5000 degrees Celsius2. Liquid Outer Core

Made of liquid Nickel and Iron2200 degrees Celsius

MantleMantle• Molten, liquid rock (Magma)Molten, liquid rock (Magma)• Makes up about 80% of Earth’s Makes up about 80% of Earth’s

volumevolume• Ranges from 870 to 2200 degrees Ranges from 870 to 2200 degrees

CelsiusCelsius• Crust and Mantle divided by the Crust and Mantle divided by the

MohoMoho Boundary Boundary

CrustCrust• Very thin, solid layer of rockVery thin, solid layer of rock• Made of mostly Silicon & Made of mostly Silicon &

Oxygen (75%)Oxygen (75%)

What are Minerals?What are Minerals? • Naturally occurring Naturally occurring – –

not man-made, in the earthnot man-made, in the earth• Inorganic –Inorganic –

doesn’t come from living thingsdoesn’t come from living things• Always a solid –Always a solid –

has volume and shapehas volume and shape

• Definite chemical composition –Definite chemical composition – made of a single pure made of a single pure

substance or elementsubstance or element• Crystalline form –Crystalline form –

flat sides, sharp edges & flat sides, sharp edges & cornerscorners

Formation & CompositionFormation & Composition • As hot magma cools, the As hot magma cools, the

minerals will crystallize.minerals will crystallize.• If the magma cools very slowly it If the magma cools very slowly it

forms large crystals. If it cools forms large crystals. If it cools very quickly it forms tiny to very quickly it forms tiny to microscopic crystals.microscopic crystals.

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

• The eight most common elements The eight most common elements in the crust form a large number of in the crust form a large number of the known minerals. the known minerals.

(O, Si, Al, Fe, Ca, Na, K, & Mg)(O, Si, Al, Fe, Ca, Na, K, & Mg)• The compound formed by Silicon & The compound formed by Silicon &

Oxygen is known as Oxygen is known as SilicateSilicate..

Mineral IdentificationMineral Identification • The identification of a The identification of a

mineral is based on its mineral is based on its physical propertiesphysical properties

1.1. ColorColor• Some minerals have characteristic Some minerals have characteristic

colorscolors

• Some minerals can come in several Some minerals can come in several different color varietiesdifferent color varieties

EX: Quartz & Corundum

Some of the colors can change due to temperature, pollution, or radiation.

2.2. LusterLuster• The way a mineral reflects light The way a mineral reflects light

off its surface.off its surface.• 2 types2 typesA. Metallic – very shiny, looks like a metal

B.B. Non-metallic -Non-metallic -

Glassy – shiny, transparent, translucentGlassy – shiny, transparent, translucent

• Earthy - clay-like, dullEarthy - clay-like, dull

• Pearly:Pearly: pearl-like pearl-like

3.3. HardnessHardness• The ability for a mineral to The ability for a mineral to

resist being scratched.resist being scratched.

Mohs Hardness Scale

• A list of ten minerals ranked A list of ten minerals ranked according to hardness.according to hardness.

1= softest (talc)1= softest (talc)

10=hardest (diamond)10=hardest (diamond)

1. Talc 2. Gypsum 3. Calcite4. Fluorite

5. Apatite6. Feldspar 7. Quartz 8. Topaz

9. Corundum10. Diamond

• A mineral that is higher on the scale A mineral that is higher on the scale will scratch the mineral that is lower.will scratch the mineral that is lower.

• Other common items have been given Other common items have been given ratings on the scale for identification ratings on the scale for identification purposes.purposes.

• EX: Fingernail, Penny, File, GlassEX: Fingernail, Penny, File, Glass

4.4. StreakStreak• The color of the powder scraped off a The color of the powder scraped off a

mineral when rubbed against a rough mineral when rubbed against a rough surface (streak plate.) surface (streak plate.)

• Very useful property for showing the TRUE Very useful property for showing the TRUE color.color.

• Same color always, no matter what the Same color always, no matter what the variation variation

5.5. BreakageBreakage 2 types –2 types –

a. Cleavage - breaks in smooth, definite a. Cleavage - breaks in smooth, definite surfacessurfaces

• Same every timeSame every time

b. Fracture - breaks in rough or jagged b. Fracture - breaks in rough or jagged surfacessurfaces

6.6. Crystal FormCrystal Form• Geometric crystals with Geometric crystals with

flat surfaces and definite flat surfaces and definite edgesedges

• CubicCubic• HexagonalHexagonal• TetragonalTetragonal• OrthorhombicOrthorhombic• MonoclinicMonoclinic• TriclinicTriclinic

• Different from cleavageDifferent from cleavage

7.7. Other PropertiesOther Properties1. 1. Reaction to Acid -Reaction to Acid -

some minerals will bubble some minerals will bubble in acidin acid

2. 2. Magnetism - Magnetism - some special minerals some special minerals

will be magneticwill be magnetic3. 3. Smell - Smell -

some will have distinct odorssome will have distinct odors4. 4. Taste -Taste -

some have a distinct tastesome have a distinct taste

Sulfur

Halite

Calcite

Mineral GroupsMineral Groups1. Silicates1. Silicates

• Most common mineral familyMost common mineral family

• Silicon-oxygen tetrahedron (SiOSilicon-oxygen tetrahedron (SiO44) )

along with additional elements.along with additional elements.

• Joined together into chains, sheets, Joined together into chains, sheets, or 3-demensional networks.or 3-demensional networks.

EXAMPLES: Feldspars, Quartz, MicasEXAMPLES: Feldspars, Quartz, Micas

2. Carbonates2. Carbonates• Carbonates are used in cement & lime.Carbonates are used in cement & lime.

• Made of Carbonate (COMade of Carbonate (CO33) with other ) with other

elements.elements.

EXAMPLES: Calcite & DolomiteEXAMPLES: Calcite & Dolomite

3. Halides3. Halides• Used in steel making, fertilizer, & saltUsed in steel making, fertilizer, & salt

EXAMPLES: Halite & FluoriteEXAMPLES: Halite & Fluorite

4. Sulfates4. Sulfates• Used in plaster.Used in plaster.

• Made of Sulfate (SOMade of Sulfate (SO44) with other ) with other

elements.elements.

EXAMPLE: GypsumEXAMPLE: Gypsum

5. Oxides5. Oxides• Have Oxygen as a major component.Have Oxygen as a major component.

EXAMPLES: Hematite, Magnetite, EXAMPLES: Hematite, Magnetite, Corundum, & Ice Corundum, & Ice

6. Native Elements6. Native Elements• Minerals of great economic value that Minerals of great economic value that

are pure elements.are pure elements.

EXAMPLES: Gold, Silver, Diamond (C), EXAMPLES: Gold, Silver, Diamond (C), Sulfur, Graphite (C), Sulfur, Graphite (C),

Copper, Copper, PlatinumPlatinum

Uses for MineralsUses for Minerals1. Ores1. Ores

Minerals or combinations of minerals from Minerals or combinations of minerals from which metals and nonmetals can be which metals and nonmetals can be removed in usable amounts.removed in usable amounts.

Examples: Examples: Cinnabar (Mercury), Cinnabar (Mercury),

Bauxite (Aluminum),Bauxite (Aluminum),

Hematite (Iron)Hematite (Iron)

• Smelting- when an ore is heated so that Smelting- when an ore is heated so that a metal can be separated from it.a metal can be separated from it.

• Alloys- when pure metals are combined Alloys- when pure metals are combined to form other metallic substances. to form other metallic substances. (Steel (Steel & Brass)& Brass)

2. 2. GemstonesGemstones• Minerals that are hard, Minerals that are hard, beautiful, and durable. beautiful, and durable.

• They are substances that can They are substances that can be be cut & polished for cut & polished for jewelry & decoration.jewelry & decoration.

a. Precious Stonesa. Precious Stones• The rarest & most valuable.The rarest & most valuable.

Ex: Diamonds, Rubies, Opals, Ex: Diamonds, Rubies, Opals, Sapphires, & EmeraldsSapphires, & Emeralds

b. Semiprecious Stonesb. Semiprecious Stones• The other gemstonesThe other gemstones

Ex:Ex: Amethysts, Zircons, Garnets, Amethysts, Zircons, Garnets, Turquoises, Jades, & moreTurquoises, Jades, & more

c. Non-Mineral Gemstonesc. Non-Mineral Gemstones• Come from living thingsCome from living things

Ex:Ex: Amber, Pearls, & CoralAmber, Pearls, & Coral