Download MINERALS

MINERALS
http://www.youtube.com/watch?v=
TYvye0CVbU0
Matter
• anything that has mass and takes up
space
• Matter is composed of elements
Element
• A substance that cannot be broken down
into simpler substances by ordinary
chemical means
Composition of Earth’s Crust
ESRT Page 1
A grouping of atoms - Molecule
Most common molecule in Earth’s crust
• Silica Tetrahedron
Composed of …
1 silicon atom
4 oxygen atoms
Silica Structure
4 oxygen atoms for
every 1 silicon atom
Olivine
Pyroxenes
(Augite)
Amphibole
(Hornblende)
Micas
Feldspar,
Quartz
Complexity
Temp.
MINERALS
• Naturally occurring
• Inorganic (never
alive)
• Definite chemical
composition
• Crystal structure
because of the
internal
arrangement of
atoms
A mineral is the
building block of rocks
Native Minerals
– Made of single
elements
• Gold (Au)
• Copper (Cu)
• Sulfur (S)
Compound
Minerals
– Made of two or
more elements
• Silicate Family
– A compound of
silicon and
oxygen
– 90% of the
Earth’s crust is
composed of
silicates
Examples:
–
Quartz SiO2
–
Olivine (Fe,Mg)2Sio4
Graphite
Diamond
Chemical formula:
C
Chemical formula:
C
How can 2 minerals with the same composition be
so different?
What’s the point here?
“Internal Arrangement of Atoms” controls most physical properties!
MINERAL PROPERTIES
FOR IDENTIFICATION
a. Color
Least dependable property because some
minerals have lots of different colors
b. Luster
Appearance of the mineral surface in
reflected light, how the mineral shines
Metallic – looks like a metal
Non-Metallic
c. Hardness
• Resistance to being scratched
• https://www.youtube.com/watch?v=b7ANc
WQEUI8
Moh’s Hardness Scale
softest
hardest
d. Streak
• Powdered form of a mineral, more reliable
than color
e. Cleavage
Tendency of minerals to split along repeated
smooth, flat planes.
Look for places where the mineral might have split along flat
and sometimes shiny planes that usually reflect light well.
Look for stairsteps, sheets, squares, cubes
e. Fracture
Mineral breaks has a jagged or
lumpy, irregular appearance
f. Crystal shape
• Geometric pattern
that a lone crystal
of the mineral will
have
SPECIAL PROPERTIES
Fluorescence – mineral glows under a black light
Double refraction
Magnetism – some minerals are
attracted to a magnet
Taste – DO NOT EVER TASTE A MINERAL
Reaction to acids
Calcite and Dolomite will bubble when Hydrochloric Acid
All mineral properties are
determined by
• The internal arrangement
of atoms
ROCK
Composed of one or more minerals
Classified by
1. Origin – how they were formed
2. Mineral Content
3. Texture
3 Types
• Igneous
• Sedimentary
• Metamorphic
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