What is the difference in picture A and B? (Other than the obvious) A B
What is a mineral?• Formed by natural processes such as cooling magma and evaporating saltwater• Inorganic – not made by life processes. Not alive.• Element or a compound with definite chemical composition (structure)• Solid and crystalline (atoms in patterns that repeat over and over again)
S.N.I.F.E.Solid-not liquid, gas, or plasmaNaturally Occurring-Not manmadeInorganic–Not alive, never wasFixed Composition - Same recipeeverywhere, every timeElement or Compound-Not amixture
How are minerals classified? Minerals are groupedbased on crystal systems.This means that they are classified according to their type of repeated crystal patterns.
How are minerals identified?(How can you tell them apart?)• Color• Hardness • Streak• Luster • Breakage• Specific • Unique Gravity properties
Color• The appearance of color of a mineral.• Minerals can also change colors when they react with air or water.• Color is NOT very reliable for identifying minerals because colors can vary greatly and are not consistent.• Streak tests are much more reliable.
HardnessHardness is determined byhow easily a mineral can be scratched.Mohs Scale of Hardness is used to measure the hardness of a mineral
Mohs Hardness Scale Mohs Scale Hardness Hardness of Common ObjectsTalc (softest) 1 Fingernail 2.5Gypsum 2 Piece of copper 2.5-3.0Calcite 3 Iron nail 4.5Fluorite 4 Glass 5.5Apatite 5 Steel file 6.5Feldspar 6 Streak plate 7.0Quartz 7 Flint sandpaperTopaz 8 Spinel (rock shops)Corundum 9 Emery sandpaperDiamond (hardest) 10 Carborundum sandpaper
Luster The way a mineral reflects light (dull or shiny).Metallic or Nonmetallic
Density• D=M/V -g/cm3• Is a measure of how much matter is in a given object.
Specific Gravity The Density of the mineral in comparison to the Density of an equalvolume of water (1g/cm3).
• -Ex: Gold’s density is 19g/cm3. What is its Specific Gravity?• SG=19g/cm3 divided by 1g/cm3• SG=19
StreakThe color of a mineral when it is in powdered form. Tested by streaking the mineral across another object (object must be harder than the mineral)
BreakageClevage-breaks along smooth, flat surfaces Fracture-breaks with an uneven, rough, or jagged surface
Unique Properties Many minerals have uniquecharacteristics that can also be used to identify the mineral. Example-natural magnet, double refraction, odor, taste, reaction to acids, fluorescence, etc.
Uses of Minerals• Minerals are a component of everyday life because they are a part of everyday objects• Jewerly (gems-rare minerals)• Diamonds are used in industrial abrasives and cutting tools• Some minerals are used to produce specific types of laser light• Quartz is used in electronics• Minerals that contain useful substances can be mined (Ex. Bauxite-aluminum; Ilemenite and Rutile-titanium)