MineralsMinerals

Chapter 3Chapter 3

MineralsMinerals – naturally occurring, inorganic – naturally occurring, inorganic solid with a definite structure and solid with a definite structure and compositioncomposition

Over 4000 mineralsOver 4000 minerals 5 Characteristics of Minerals:5 Characteristics of Minerals:

1. formed by natural processes – salt, diamonds1. formed by natural processes – salt, diamonds 2. Inorganic – no Carbon2. Inorganic – no Carbon 3. Solids3. Solids 4. Unique chemical composition4. Unique chemical composition 5. repeated pattern5. repeated pattern

CrystalsCrystals – solid with atoms are arranged in – solid with atoms are arranged in repeating patternsrepeating patterns

Minerals formed:Minerals formed: 1. from magma – cooling of hot melted rock1. from magma – cooling of hot melted rock 2. liquid evaporating - crystals 2. liquid evaporating - crystals

SilicatesSilicates – minerals that contain silicon and – minerals that contain silicon and oxygen and usually one or more other elementsoxygen and usually one or more other elements

Silicon and Oxygen the two most abundant Silicon and Oxygen the two most abundant elements in earths crustelements in earths crust

Mineral IdentificationMineral Identification 1. 1. Physical PropertiesPhysical Properties – –

ColorColor AppearanceAppearance Hardness Hardness – Mohr hardness scale– Mohr hardness scale LusterLuster – how light is reflected – how light is reflected

Metallic or non metallicMetallic or non metallic StreakStreak – color of the mineral when it is broken up – color of the mineral when it is broken up

and powderedand powdered Cleavage and fractureCleavage and fracture – how it breaks – how it breaks

Cleavage – breaks along smooth flat surfaces MicaCleavage – breaks along smooth flat surfaces Mica Fracture – rough, jagged edge - QuartzFracture – rough, jagged edge - Quartz

LusterLuster – how light is reflected – how light is reflectedMetallic or non metallicMetallic or non metallic

StreakStreak – color of the mineral – color of the mineral when it is broken up and when it is broken up and

powderedpowdered

Hardness Hardness

3.2 How Minerals Form3.2 How Minerals Form In crystallization the atoms are In crystallization the atoms are

arranged either by:arranged either by: 1. Magma and Lava1. Magma and Lava

Hot magma cools inside the earthHot magma cools inside the earth Lava (magma on the surface) hardens on Lava (magma on the surface) hardens on

the surfacethe surface Both form crystals when they cool to a Both form crystals when they cool to a

solidsolid 2. Solution2. Solution

Elements and compounds dissolved in Elements and compounds dissolved in water leave a solution they form crystalswater leave a solution they form crystals

Minerals form by evaporationMinerals form by evaporation Salt, halite, gypsum, calciteSalt, halite, gypsum, calcite

Minerals from Hot Water SolutionsMinerals from Hot Water Solutions Elements and compounds dissolveElements and compounds dissolve VeinVein – narrow channel or slap of a – narrow channel or slap of a

mineral different from the surrounding mineral different from the surrounding rockrock

3.3 Mineral Resources3.3 Mineral Resources Uses of Minerals:Uses of Minerals: 11. Gemstones. Gemstones – hard, colorful, mineral with – hard, colorful, mineral with

a glassy lustera glassy luster 2. 2. Metals Metals – aluminum, iron, copper or silver– aluminum, iron, copper or silver 3. Misc: 3. Misc: TalcTalc for talcum powder for talcum powder

Calcite Calcite for optical instruments like for optical instruments like microscopesmicroscopes

Quartz Quartz for class and electronicsfor class and electronics Gypsum - Gypsum - wallboard and cementwallboard and cement

4. 4. OreOre – – rock that contains a useful rock that contains a useful mineral that can be sold for profitmineral that can be sold for profit