geos 111 minerals

MINERALS


Chemical
composition of the
Crust
Oxygen most abundant- 46.6%
Followed by silicon and
aluminum
Iron, Calcium, Sodium,
Potassium, Magnesium
The most common minerals
will be composed mostly of
these elements
Silica & silicates


MINERAL vs. ROCK
ROCK
An aggregate of one or more MINERALS
(usually- coal, organic)

MINERAL
Solid
Crystalline- orderly arrangement of atoms
Naturally occurring
Inorganic
Definite chemical composition

e.g. SiO2 for quartz; KAlSi3O8 for feldspar

Atom & Elements
Atoms
Neutral
Nucleus
Proton, neutron

Electron

Ions
Electrical Charge

Molecule- e.g. water molecule





Chemical activity
Stable atoms want
positive & negative charges balanced
electron shells full

Ions- positive (Cations) and negative (Anions)
Bonding
Ionic
Covalent
Metallic
Van der Waal’s

Element
Atomic number
Number of PROTONS

Isotope
Differing number of
NEUTRONS

Atomic weight
Mass of PROTONS and
NEUTRONS


Crystallinity
3 dimensional orderliness of atoms
Silicon-oxygen tetrahedron
Silicate structures
Single- e.g. olivine
Chain
Single chain- pyroxene
Double chain- amphibole

Sheet- e.g. mica, clay
Framework- e.g. quartz, feldspar

MINERALS
Crystalline solids
Natural and Inorganic Substances
Definite chemical composition
Can be written as a chemical
formula
Solid solution (within a range)




Important Minerals
Quartz (most abundant)
FELDSPAR Group
Potassium Feldspar - Orthoclase
Plagioclase Feldspar
Sodium (Na) Albite
Calcium (Ca) Anorthosite