minerals: properties and uses. a mineral is naturally occurring naturally occurring inorganic (not...
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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!