Minerals and Minerals and Mineral Mineral

IdentificationIdentificationBy Mr. KingBy Mr. King

WhatWhat is a mineral?is a mineral?

•InorganicInorganic

•Naturally occurring Naturally occurring

•Crystalline structureCrystalline structure

•Chemical compositionChemical composition

•Distinct physical propertiesDistinct physical properties

Mineral propertiesMineral properties•ColorColor

•LusterLuster

•Habit (Shape)Habit (Shape)

•Cleavage & FractureCleavage & Fracture

•StreakStreak

•HardnessHardness

•OtherOther

Color:Color: Not mineral Not mineral specificspecific

Luster:Luster:How minerals reflect lightHow minerals reflect light

Non-metallic

Metallic

Mineral Habit Mineral Habit (Shape)(Shape)

Shape a Shape a mineral takes mineral takes if grown if grown unimpededunimpeded

CleavageCleavage

Cleavage is the breakage Cleavage is the breakage along planes that cut across along planes that cut across weak bonds, thus cleavage weak bonds, thus cleavage in controlled by the in controlled by the mineral’s atomic structuremineral’s atomic structureEG: rhombohedral calciteEG: rhombohedral calcite

FractureFracture

Fractures occur in minerals Fractures occur in minerals whose bond strengths are the whose bond strengths are the same in all directions thus same in all directions thus breakage doesn’t follow a breakage doesn’t follow a crystallographic direction, but crystallographic direction, but follows an irregular surface.follows an irregular surface.

EG: conchodial fracture in EG: conchodial fracture in quartzquartz

CleavageCleavage

There is a visual difference There is a visual difference between the cleavage and between the cleavage and fracture in a mineral ... Just fracture in a mineral ... Just

waitwait

Streak:Streak:

The powdered form of a mineralThe powdered form of a mineral

Other PropertiesOther Properties•Specific Specific

gravitygravity•Reaction to Reaction to

acidacid•StriationsStriations•MagnetismMagnetism•FluorescenceFluorescence