MINERALS
I
MINERALS ARE MADE UP OF SINGLE ELEMENTS OR COMPOUNDS
A) ELEMENTS- A SUBSTANCE THAT CANNOT BE BROKEN DOWN TO
ANY SIMPLER SUBSTANCE; MADE UP OF ATOMS
B) EIGHT MOST COMMON ELEMENTS IN THE EARTH’S CRUST:
1) O
5) CA
2) SI
6) NA
3) AL
7) K
4) FE
8) MG
C) ATOM- SMALLEST PART OF AN ELEMENT; HAS ALL THE
PROPERTIES THE ELEMENT HAS BUT CANNOT BE SEEN WITH
TOOLS
II
A MINERAL IS:
A) NATURALLY OCCURRING
B) DEFINITE CHEMICAL COMPOSITION
C) INORGANIC SOLID
D) CRYSTALLINE STRUCTURE
E) DEFINITE SET OF PHYSICAL PROPERTIES
III
FAMILIES OF MINERALS
A) MINERALS COMPOSED OF SINGLE ELEMENTS ARE CALLED
NATIVE MINERALS.
 AU = GOLD
 SILVER = AG
 COPPER = CU
 SULFUR = S
 GRAPHITE OR DIAMOND = C
B) MOST MINERALS ARE COMPOSED OF TWO OR MORE ELEMENTS
 HALITE- NACL
 QUARTZ- SiO
C) SILICATES
1) OXYGEN AND SILICON COMBINE READILY WITH EACH OTHER AND WITH
OTHER ELEMENTS TO FORM THIS FAMILY OF MINERALS
2) MOST COMMON FAMILY OF MINERALS AND MAKE UP OVER 90% OF ALL
MINERALS
3)
THIS IS BECAUSE OXYGEN AND SILICON ARE THE MOST COMMON
ELEMENTS IN THE EARTH’S CRUST
III
PHYSICAL PROPERTIES OF MINERALS
A) COLOR- LEAST USEFUL PROPERTY, CHANGE IN THE CHEMICAL
FORMULA WILL VARY THE COLOR OF THE MINERAL. (QUARTZ)
B) LUSTER1) METALLIC- LOOKS LIKE METAL IN THE WAY THE MINERAL REFLECTS
LIGHT (GALENA OR PYRITE)
2) 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 THE MINERALS SURFACE (OPAL, GARNET)
WAXY- DULL SHINE LIKE CANDLE WAX (SULFUR, OLIVINE)
EARTHY- NO SHINE AT ALL (BAUXITE)
ADAMANTINE- BRILLIANT GLOW, BEAM OF LIGHT AT A
CERTAIN ANGLE (DIAMOND)
C) STREAK- THE COLOR OF A MINERALS POWDER
1) RUB THE MINERAL AGAINST A STREAK PLATE AND OBSERVE THE
POWDER’S COLOR
D) BREAKAGE PATTERN
1) CLEAVAGE- TENDENCY OF A MINERAL TO SEPARATE
ALONG PLANES OF WEAKNESS
 ONE PLANE OF WEAKNESS = BASAL (MICA)
 TWO PLANES OF CLEAVAGE AT 90* (ORTHOCLASE)
 THREE PLANES OF WEAKNESS AT 90* = CUBIC (HALITE)
 THREE PLANES NOT AT 90* = RHOMBOHEDRAL (CALCITE)
2) 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 (ASBESTOS)
D) HARDNESS- RESISTANCE TO BE SCRATCHED; IS VERY USEFUL
SINCE A MINERAL’S HARDNESS IS CONSTANT
1) FRIEDRICH MOH DEVELOPED A SCALE
FINGERNAIL IS A 2.5
STEEL NAIL IS A 5.0
GLASS IS A 5.5
IV
SPECIAL PROPERTIES
A) MAGNETIC- THE ABILITY TO ATTRACT A MAGNET (MAGNETITE)
B) EFFERVESCENCE- adding HCl to a mineral may cause it to fizz.
(Calcite)
C) TASTE- HALITE TASTES SALTY
C) ODOR- SOMETIMES THE POWDER OF A MINERAL HAS A CERTAIN ODOR
(SULFUR SMELLS LIKE ROTTEN EGGS)
D) MAGNETISM- MAGNET IS ATTRACTED TO MINERAL (MAGNETITE)
E) Fluorescence- ability to glow under aN ULTRAVIOLET light
(Sphalerite)
F) DOUBLE REFRACTION- SPLITS LIGHT RAYS (CALCITE)
G) SPECIFIC GRAVITY (DENSITY)- SOME MINERALS HAVE ATOMS
VERY TIGHTLY PACKED, AND FEEL HEAVIER BECAUSE THEY ARE
MORE DENSE (GALENA)
NAME_____________________
DATE________________
MINERALS QUIZ
WHAT IS MATTER? (7) WHAT IS IT COMPOSED OF? (3)
NAME THE THREE COMPONENTS OF AN ATOM AND WHERE THEY ARE
FOUND. (6),(4)
LABEL THE DRAWING AND DEFINE EACH. (4),(6)
CAN ATOMS HAVE THE SAME NUMBER OF PROTONS BUT A DIFFERENT
NUMBER OF NUETRONS? IF SO WHY? (4),(6)
5) WHAT IS A MINERAL? (10)
MOST MINERALS FORM OUT OF MAGMA. WHAT DETERMINES THESE
MINERALS CRYSTAL SIZE AND HOW? (5),(5)
WHAT ARE THE SIX CRYSTAL SYSTEMS? (10)
A) WHAT IS THE LEAST USEFUL PROPERTY FOR IDENTIFYING MINERALS?
(2)
B) WHAT IS STREAK? (4)
NAME FOUR KINDS OF LUSTER? (4)
DESCRIBE CLEAVAGE AND NAME ONE MINERAL THAT HAS CLEAVAGE?
(8),(2)
FILL IN MOH’S SCALE OF HARDNESS FROM SOFTEST TO HARDEST.
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