Post on 24-Dec-2015
MINERALS ARE MADE UP OF SINGLE ELEMENTS OR COMPOUNDS
ELEMENTS A SUBSTANCE THAT CANNOT BE BROKEN DOWN TO ANY SIMPLER SUBSTANCE
EIGHT MOST COMMON ELEMENTS IN THE EARTH’S CRUST:
1.) OXYGEN 46% 3-8.)THE REMAINING 25% IS
COMPOSED OF Al, Fe, Ca, Na, K, Mg
2.) SILICON 29%
A MINERAL IS:
1.) NATURALLY OCCURRING
2.) DEFINITE CHEMICAL COMPOSITION
3.) INORGANIC SOLID
4.) CRYSTALLINE STRUCTURE
5.) DEFINITE SET OF CHEMICAL AND PHYSICAL PROPERTIES
FAMILIES OF MINERALS
Native Minerals ARE COMPOSED OF SINGLE ELEMENTS.
Au (aurum) GOLD
Ag (argentium) SILVER
Cu (cuprum) COPPER
S SULFUR
C GRAPHITE OR DIAMOND
MOST MINERALS ARE COMPOSED OF TWO OR MORE ELEMENTS
HALITE (NaCl)
QUARTZ (SiO2)
• OXYGEN AND SILICON COMBINE READILY WITH EACH OTHER AND WITH OTHER ELEMENTS TO FORM THIS FAMILY OF MINERALS
• MOST COMMON FAMILY OF MINERALS AND MAKE UP OVER 90% OF ALL MINERALS
• THIS IS BECAUSE OXYGEN AND SILICON ARE THE MOST COMMON ELEMENTS IN THE EARTH’S CRUST
* ANY MINERAL WHICH IS A SILICATE MUST CONTAIN Si (SILICON) AND O (OXYGEN) IN THEIR CHEMICAL FORMULA
NOW CIRCLE ALL OF THE MINERALS ON YOUR NOTESHEET WHICH ARE SILICATES
ORTHOCLASE AUGITE
QUARTZ OLIVINE
BIOTITE
LEAST USEFUL PROPERTY, CHANGE IN THE CHEMICAL FORMULA WILL VARY THE COLOR OF THE MINERAL. (QUARTZ)
SiO2
ROSE QUARTZCONTAINS TITANIUM OXIDE AND MANGANESE
OXIDE TO MAKE A ROSE COLOR CRYSTAL QUARTZ
METALLIC- LOOKS LIKE METAL IN THE WAY THE MINERAL REFLECTS LIGHT (GALENA OR PYRITE)
- THE WAY A MINERAL SHINES IN REFLECTED LIGHT.
NON-METALLIC- DOES NOT LOOK LIKE POLISHED METAL, SO OTHER TERMS ARE USED
VITREOUS- SHINY, GLASSLIKE (QUARTZ)
• PEARLY LOOKS LIKE PEARLS WHEN LIGHT IS REFLECTED OFF OF THE SURFACE (OPAL)
EARTHY- NO SHINE AT ALL (BAUXITE)
ADAMANTINE- BRILLIANT GLOW, BEAM OF LIGHT AT A CERTAIN ANGLE (DIAMOND)
WAXY- DULL SHINE LIKE CANDLE WAX (SULFUR, OLIVINE)
THE COLOR OF A MINERALS POWDER
RUB THE MINERAL AGAINST A STREAK PLATE AND OBSERVE THE POWDER’S COLOR
HOW DO YOU FIND THE STREAK COLOR OF A MINERAL?
CLEAVAGE- TENDENCY OF A MINERAL TO SEPARATE ALONG PLANES OF WEAKNESS
ONE PLANE OF WEAKNESS BASAL CLEAVAGE (MICA)
TWO PLANES OF CLEAVAGE AT 90* (ORTHOCLASE)
FRACTURE- NO PLANES OF WEAKNESS SO THE MINERAL BREAKS ALONG IRREGULAR SURFACES
CONCHOIDAL- SURFACES ARE SOMEWHAT ROUNDED, SHELL-LIKE (QUARTZ)
UNEVEN- ROUGH SURFACE, NO DISTINGUISHABLE PATTERN
FIBROUS- JAGGED SURFACE LIKE FIBERS (WOLLASTONITE)
RESISTANCE TO BE SCRATCHED; IS VERY USEFUL SINCE A MINERAL’S HARDNESS IS CONSTANT
• SCALE TO MEASURE HARDNESS WAS DEVELOPED BY FRIEDRICH MOH IN 1812
• HARDNESS IS MEASURED ON A SCALE FROM 1 BEING THE LOWEST TO 10 BEING THE HIGHEST.
• TO DETERMINE THE HARDNESS OF A MINERAL YOU MUST TRY TO SCRATCH THE MINERAL AGAINST A GLASS PLATE
FINGERNAIL IS A 2.5
GLASS IS A 5.5
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TALC TALCUM POWDER, BABY POWDER
GYPSUM BUILDING MATERIALS (SHEETROCK)
CALCITE CEMENTS
FLUORITE TOOTHPASTE
APATITE FERTILIZER
FELDSPAR FLOOR TILES
QUARTZ WATCHES, ABRASIVES
TOPAZ GEMSTONES (EMERALD)
CORUNDUM GEMSTONES (RUBY & SAPHIRE)
DIAMOND SAW BLADES, “AGIRL’S BEST FRIEND”
MINERAL NAME TYPICAL USES
• EFFERVESCENCE – ADDING HCL TO A MINERAL CAUSES IT TO FIZZ
• MAGNETIC – THE ABILITY TO ATTRACT A MAGNET (MAGNETITE)
• TASTE – HALITE
• ODOR – SOMETIMES THE POWDER OF A MINERAL HAS A CERTAIN ODOR (SULFUR SMELLS LIKE ROTTEN EGGS)
• DOUBLE REFRACTION – SPLITS LIGHT RAYS (CALCITE)