MineralsMineralsFormation, Characteristics and Formation, Characteristics and Identifying PropertiesIdentifying Properties

What is a Mineral?What is a Mineral?

A Naturally occurringA Naturally occurring

InorganicInorganic

HomogenousHomogenous

CrystallineCrystalline

Single solid substanceSingle solid substance

Why study minerals?Why study minerals?

Minerals are important in our everyday lives Minerals are important in our everyday lives ( go on a mineral scavenger hunt...)( go on a mineral scavenger hunt...)

Asbestos Asbestos All pictures are from:All pictures are from:

CalciteCalcitenote shape of crystalnote shape of crystal

GarnetGarnetNY State MineralNY State Mineral

DiamondDiamondThe hardest mineralThe hardest mineral

What is a crystal?What is a crystal?

A solid with a regular geometric shape A solid with a regular geometric shape resulting from the internal arrangement of resulting from the internal arrangement of atoms which make it upatoms which make it up

6 basic shapes6 basic shapes

What do all these What do all these minerals have in minerals have in common?common?

• List in your notes:List in your notes:

Crystal Shapes: (see Crystal Shapes: (see handout)handout)

Crystal shape is due to the molecular Crystal shape is due to the molecular arrangement of atomsarrangement of atoms

Shapes include: Shapes include:

How Do Minerals Form?How Do Minerals Form?

Cooling of magma (crystallization)Cooling of magma (crystallization)

Heat and pressure (recrystallization)Heat and pressure (recrystallization)

Evaporates or precipitates from seawaterEvaporates or precipitates from seawater

Cooling from magmaCooling from magma

What Determines the What Determines the Size of the Size of the Crystal/Mineral?Crystal/Mineral?

Cooling timeCooling time

coarse or large crystals coarse or large crystals have a long cooling timehave a long cooling time

fine or small crystals have a fine or small crystals have a short cooling timeshort cooling time

Identifying Minerals:Identifying Minerals:

We use observable and testable characterics to We use observable and testable characterics to identify mineralsidentify minerals

Easily Observable Easily Observable Characteristics:Characteristics:

ColorColor

Luster(way the Luster(way the mineral reflects mineral reflects light)light)

Crystal ShapeCrystal Shape

Testable Characteristics:Testable Characteristics:

Hardness (Moh’s Hardness (Moh’s Scale)Scale)

Streak (color of Streak (color of mineral in powdered mineral in powdered form)form)

Acid TestAcid Test

Cleavage vs. FractureCleavage vs. Fracture

Specific Gravity Specific Gravity

FluorescenceFluorescence

ColorColor

This is the least This is the least reliable property to reliable property to use to identify a use to identify a mineralmineral

LusterLuster

Metallic orMetallic or

Non-metallicNon-metallic

StreakStreak

Rub mineral along Rub mineral along porcelain streak porcelain streak plateplate

Moh’s Scale Moh’s Scale

Cleavage vs. FractureCleavage vs. Fracture

This is the way the This is the way the mineral breaks -if it mineral breaks -if it breaks along a breaks along a plane then it plane then it cleaves, if it cleaves, if it shatters then it shatters then it fracturesfractures

Use these tests to help Use these tests to help you identify minerals in you identify minerals in lab...lab...

Other mineral Other mineral properties-properties-Flourescence-Flourescence-These minerals glow under These minerals glow under special lightspecial light

Double refraction-bendsDouble refraction-bends light so words appear twice light so words appear twice (calcite)(calcite)

MagnetismMagnetismAre magneticAre magnetic

Specific gravity-Specific gravity- density density of mineral compared to of mineral compared to waterwater

Mineral FamiliesMineral FamiliesNative Elements: consist of a single elementNative Elements: consist of a single element

Halides: consist of a metal plus a halogen Halides: consist of a metal plus a halogen (noble gas-Cl, F, Ne, He)(noble gas-Cl, F, Ne, He)

Carbonates: consist of a metal and Carbonates: consist of a metal and carbonate group (COcarbonate group (CO33))

Sulfides: consist of metal and sulfurSulfides: consist of metal and sulfur

Sulfates: consist of a metal and sulfate group Sulfates: consist of a metal and sulfate group (SO(SO44))

Oxides: consist of metal and oxygenOxides: consist of metal and oxygen

Silicates: consist of silicon and oxygen (SiOSilicates: consist of silicon and oxygen (SiO44 or SiOor SiO22))

Other facts:Other facts:Rare minerals of great beauty and value are Rare minerals of great beauty and value are

classified as gems (ex: diamonds, rubies)classified as gems (ex: diamonds, rubies)

Minerals that have a commercial value and Minerals that have a commercial value and use and can be extracted from the earth use and can be extracted from the earth are ores. These are usually metals. (ex: are ores. These are usually metals. (ex: lead, iron)lead, iron)

We are studying minerals or mineralologyWe are studying minerals or mineralology