Minerals: Properties and UsesMinerals: Properties and Uses

A Mineral isA Mineral is

Naturally occurringNaturally occurring Inorganic (not made from animals or Inorganic (not made from animals or

plants)plants) SolidSolid with a definite chemical composition with a definite chemical composition

(formula)(formula) and an orderly arrangement of atoms and an orderly arrangement of atoms

(crystal structure)(crystal structure)

Crystal StructureCrystal Structure

What determines the use or uses What determines the use or uses of a particular mineral?of a particular mineral?

Use is determined byUse is determined by physical propertiesphysical properties chemical compositionchemical composition

What are physical properties?What are physical properties? ColorColor LusterLuster

– MetallicMetallic– NonmetallicNonmetallic

StreakStreak– Color of the powdered mineralColor of the powdered mineral

HardnessHardness– Moh’s Scale from 1-10Moh’s Scale from 1-10

BreakageBreakage– CleavageCleavage– FractureFracture

Physical PropertiesPhysical Properties

Unique combinations for each mineralUnique combinations for each mineral Useful for IdentificationUseful for Identification Determine some usesDetermine some uses

Use determined byUse determined byphysical propertiesphysical properties

Chemical composition is of little concern.Chemical composition is of little concern. Specific physical properties are the basis for Specific physical properties are the basis for

use.use. Examples:Examples:

– Quartz for its hardness: sand paperQuartz for its hardness: sand paper– Talc for its absorbency: baby powderTalc for its absorbency: baby powder– Graphite for its softness: pencil “leads”Graphite for its softness: pencil “leads”– Halite for its tasteHalite for its taste

GraphiteGraphite

TalcTalc

Some minerals are used for their Some minerals are used for their chemical compositionchemical composition

Physical properties are of little concernPhysical properties are of little concern Chemical composition is important because Chemical composition is important because

certain minerals are sources of valuable certain minerals are sources of valuable chemical elements or are of use by chemical elements or are of use by themselves.themselves.

Examples of minerals used for Examples of minerals used for their chemical compositiontheir chemical composition

Gold – jewelry, dentistry, electronicsGold – jewelry, dentistry, electronics

Examples of minerals used for Examples of minerals used for their chemical compositiontheir chemical composition

Hematite, magnetite, limonite – iron and Hematite, magnetite, limonite – iron and steelsteel

Examples of minerals used for Examples of minerals used for their chemical compositiontheir chemical composition

Malachite, azurite, chrysocolla – copper: Malachite, azurite, chrysocolla – copper: wires, pennies, electronicswires, pennies, electronics

Examples of minerals used for Examples of minerals used for their chemical compositiontheir chemical composition

Gold – jewelry, dentistry, electronicsGold – jewelry, dentistry, electronics Hematite, magnetite, limonite – iron and Hematite, magnetite, limonite – iron and

steelsteel Malachite, azurite, chrysocolla – copper: Malachite, azurite, chrysocolla – copper:

wires, pennies, electronicswires, pennies, electronics Galena – lead, formerly plumbing and Galena – lead, formerly plumbing and

paints, now – mostly chemicals industrypaints, now – mostly chemicals industry Bauxite – aluminum: cans, foil, bikes, Bauxite – aluminum: cans, foil, bikes,

aircraft, etc.aircraft, etc.

Abundance of chemical elements Abundance of chemical elements in Earth’s Crustin Earth’s Crust

O – 46.6%O – 46.6% Si – 27.7%Si – 27.7% Al – 8.1%Al – 8.1% Fe – 5.0%Fe – 5.0% Ca – 3.6%Ca – 3.6% Na – 2.8%Na – 2.8% K – 2.6%K – 2.6% Mg – 2.1%Mg – 2.1% Other – 1.7%Other – 1.7%

Other Chemical ElementsOther Chemical Elements

1.7% of crust1.7% of crust Highly usefulHighly useful Highly valuableHighly valuable Example: Copper – average crustal Example: Copper – average crustal

abundance is 50 ppm, but the US alone uses abundance is 50 ppm, but the US alone uses 2 million tons per year!2 million tons per year!