Transcript 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,
Electron
Ions
Electrical
neutron
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
Important Minerals
PYROXENE Group- Augite most
common
AMPHIBOLE Group- Hornblende
most common
MICA Group- Si + O in sheets
Biotite
Muscovite
CALCITE- CaCO3
Properties of Minerals
Color
Not
always reliable (Olivine, green; Flourite,
yellow, purple, green…)
Ferromagnesian minerals green or black
Streak- powdered form
Luster- reflectance of light
Metallic
Nonmetallic
Vitreous
Earthy
or Glassy
Properties of
Minerals
Hardness- resistance to scratching
Moh’s Hardness Scale
Fingernail
= 2.5
Penny = 3.5
Knife/Glass = 5.5
Streak Plate= 6.5
Crystal Form
Law
of Constancy of Interfacial
Angles
Cleavage
Properties of
Minerals
Quality
(poor, good, perfect)
Number of directions
One-
e.g. Mica
Two at right angles- e.g. Feldspar, Pyroxene
Two not at right angles- e.g. Amphibole
Three at right angles (cubic)- e.g. Halite
Three not at right angles (rhombohedral)- e.g.
calcite
Four (Flourite) or six (Sphalerite)- not common
Properties of
Minerals
Fracture
Absence
of cleavage
Irregular fracture
Conchoidal fracture- Quartz
Density
Specific
Gravity
Some unusual properties
Striations,
refraction
Magnetism, Taste, Odor, Double
Chemical tests
Reaction with HCl
Calcite
effervesces
ROCK CYCLE
Equilibrium
Interrelationships between
igneous
rocks
sediment
sedimentary rocks
metamorphic rocks
weathering and erosion
Plate Tectonic Example
ROCK CYCLE
Equilibrium
Interrelationships between
igneous
rocks
sediment
sedimentary rocks
metamorphic rocks
weathering and erosion
Plate Tectonic Example