MineralsMineralsSection 1Section 1

MineralsMinerals

Mineral—four characteristicsMineral—four characteristics– Naturally occurring—formed by Naturally occurring—formed by

processes on or inside Earth with no processes on or inside Earth with no input from humansinput from humans

– Inorganic—not made by life Inorganic—not made by life processesprocesses

– Element or compound with a definite Element or compound with a definite chemical compositionchemical composition

– Orderly arrangement of atoms; all Orderly arrangement of atoms; all minerals are crystalline solidsminerals are crystalline solids

Crystal—solid with atoms arranged Crystal—solid with atoms arranged in orderly, repeating patternsin orderly, repeating patterns– Some crystals form from magma, hot Some crystals form from magma, hot

melted rock below the Earth’s surfacemelted rock below the Earth’s surface When magma cools slowly, crystals are When magma cools slowly, crystals are

largelarge When magma cools quickly, crystals are When magma cools quickly, crystals are

smallsmall

– Crystals can form from solutions as Crystals can form from solutions as water evaporates or if too much of a water evaporates or if too much of a substance is dissolved in water.substance is dissolved in water.

Mineral groups are defined by Mineral groups are defined by their composition.their composition.– Silicates contain silicon, oxygen, and Silicates contain silicon, oxygen, and

one or more other elements; they one or more other elements; they include most common rock-forming include most common rock-forming minerals.minerals.

– Silicon and oxygen are the two most Silicon and oxygen are the two most abundant elements in Earth’s crust; abundant elements in Earth’s crust; they form the building blocks of they form the building blocks of many minerals.many minerals.

MineralsMineralsSection 2Section 2

Mineral IdentificationMineral Identification

Color and appearance are not Color and appearance are not enough to distinguish most enough to distinguish most minerals.minerals.

Hardness is a measure of how Hardness is a measure of how easily a mineral can be scratched; easily a mineral can be scratched; the Mohs scale compares mineral the Mohs scale compares mineral hardness.hardness.

The way a mineral reflects light is The way a mineral reflects light is its luster.its luster.– Can be metallic or nonmetallicCan be metallic or nonmetallic– Nonmetallic lusters include dull, Nonmetallic lusters include dull,

pearly, silky, and glassypearly, silky, and glassy

Specific gravity is the ratio of a Specific gravity is the ratio of a mineral’s weight to the weight of an mineral’s weight to the weight of an equal volume of water; expressed as a equal volume of water; expressed as a number.number.

Streak is the color of a mineral in Streak is the color of a mineral in powdered form, but the streak test is powdered form, but the streak test is useful only for minerals softer than the useful only for minerals softer than the streak plate.streak plate.

The way a mineral breaks can be a The way a mineral breaks can be a distinguishing characteristic.distinguishing characteristic.– Minerals with cleavage break along Minerals with cleavage break along

smooth, flat surfaces.smooth, flat surfaces.– Minerals with fracture break with Minerals with fracture break with

uneven, rough, or jagged surfaces.uneven, rough, or jagged surfaces. Some minerals have unique Some minerals have unique

properties that involve light or properties that involve light or magnetism.magnetism.

MineralsMineralsSection 3Section 3

Uses of MineralsUses of Minerals

Gems—rare and beautiful Gems—rare and beautiful minerals that are highly prized.minerals that are highly prized.– The Cullinan diamond and the Hope The Cullinan diamond and the Hope

diamond are famous historical gems.diamond are famous historical gems.– Gems have industrial applications in Gems have industrial applications in

abrasives, lasers, and electronics.abrasives, lasers, and electronics.

Minerals can contain other useful Minerals can contain other useful elementselements– An ore is a mineral or rock containing a An ore is a mineral or rock containing a

substance that can be mined at a profit.substance that can be mined at a profit.– Elements must be refined, or purified, from Elements must be refined, or purified, from

ores.ores.– Some elements dissolve in fluids, travel Some elements dissolve in fluids, travel

through weakness in rocks, and in those through weakness in rocks, and in those weaknesses form mineral deposits called weaknesses form mineral deposits called vein mineral deposits.vein mineral deposits.

– Titanium is a useful element derived from Titanium is a useful element derived from the minerals ilmenite and rutile.the minerals ilmenite and rutile.