Minerals

 Rocks  Minerals  Atoms RocksMineralsAtoms Rocks, Minerals, & Elements

rocks granite  Rocks = a collection of one or more minerals quartz + feldspar + biotite minerals  Minerals = a collection of one or more elements (atoms)elements atoms quartz = silicon + oxygen Rocks, Minerals, & Elements

 There are 117 known elements (as of 2006), but only 92 occur naturally Atomic Building Blocks

 The two most common elements in the Earth’s crust is oxygen and silicon.  8 elements make up the vast majority of the crust’s composition Atomic Building Blocks Earth’s Crust

COMMON ELEMENTS IN EARTH’S CRUST Tarbuck & Lutgens

SolidSolid Occurs naturallyOccurs naturally InorganicInorganic Definite crystalline structureDefinite crystalline structure Definite chemical compositionDefinite chemical composition SOIDD – stupidity occurs in daily doses Celestian What is a Mineral?  Minerals are the combination of one or more elements

Making Minerals  Minerals can crystallize from COOLING MAGMA  Minerals can crystallize from a solution (body of water) due to  Evaporation OR  Precipitation

MINERAL GROUPS  Over 4000 known minerals  8 main mineral groups  Classified by most significant ions MAGNESITE Celestian

1. SILICATES (SiO 4 ) >90% of all minerals on Earth’s crust>90% of all minerals on Earth’s crust Composed of the silica tetrahedronComposed of the silica tetrahedron InsolubleInsoluble Common minerals:Common minerals: quartz, feldspar, mica Use: bricks, glass,Use: bricks, glass, insulation, jewelry, electronics

2. CARBONATES CO 3 Common mineral: calcite (forms the rock limestone)Common mineral: calcite (forms the rock limestone) Soluble in wet climates (cave former)Soluble in wet climates (cave former) Use: cement, fillerUse: cement, filler and whitener in plastic and whitener in plastic pipe, paper, and pipe, paper, and toothpaste toothpaste

3. SULFATES SO 4 Common mineral: gypsumCommon mineral: gypsum SolubleSoluble Uses: drywall, soil conditioner, hard cast for broken bonesUses: drywall, soil conditioner, hard cast for broken bones

4. PHOSPHATES PO 4 Common mineral: apatiteCommon mineral: apatite Use: fertilizerUse: fertilizer

5. OXIDES - O Common minerals: Hematite, magnetite, chromiteCommon minerals: Hematite, magnetite, chromite Metals combine with oxygenMetals combine with oxygen Uses: ores of iron, titanium tin, manganese, etc.Uses: ores of iron, titanium tin, manganese, etc. Hematite

6. SULFIDES - S Common minerals: Sphalerite, Cinnabar, Chalcopyrite, Galena, PyriteCommon minerals: Sphalerite, Cinnabar, Chalcopyrite, Galena, Pyrite Unstable at Earth’s surface – alter to sulfate ionsUnstable at Earth’s surface – alter to sulfate ions Cause water pollutionCause water pollution Uses: ores for zinc,Uses: ores for zinc, mercury, copper, lead, iron Pyrite

7. HALIDES – Cl, F, Br, I Common minerals: Halite, fluorite Extremely soluble Uses: salt, steel making, fertilizer Halite

8. NATIVE ELEMENTS Common minerals: Gold, silver, platinum, copper, sulfur, diamond, graphiteCommon minerals: Gold, silver, platinum, copper, sulfur, diamond, graphite Composed of a single atom typeComposed of a single atom type Use: jewelry, electrical parts, lubricants, etc.Use: jewelry, electrical parts, lubricants, etc. Gold in quartz Graphite

Luster Physical Properties of Minerals  How a mineral reflects light (metallic OR nonmetallic)

Hardness Physical Properties of Minerals  Resistance to scratching

Cleavage Physical Properties of Minerals mica calcite  Planes of weakness in a mineral

Color Physical Properties of Minerals Quartz Amethyst (purple quartz) Smokey quartz  Largely dependant on composition

Streak Physical Properties of Minerals Hematite displaying a reddish streak  The color of a mineral when powdered

higher (10-20 g/cm 3 ) lower (2-3 g/cm 3 ) Specific Gravity Physical Properties of Minerals  Density of a mineral relative to water (1.0 g/cm 3 )

Crystal Form Physical Properties of Minerals  Unique forms controlled by a mineral’s atomic structure

 effervescence effervescence  Crystal striations Others Physical Properties of Minerals  fluorescence fluorescence  magnetism magnetism