3- Mineralogy Flashcards
naturally occurring, solid earth materials formed by geologic processes
minerals
smallest part of a chemical element that can take part of a chemical reaction or combine with another atom
atom
isotopes that are unstable and undergo nuclear decay
radioisotopes
minerals must be
naturally formed
solid
characteristic chemical formula
characteristic crystalline structure
substance composed of two or more elements that can be represented by a chemical formula
compound
how to idenfy minerals
by chemical composition and physical characteristics
attraction between atoms, sharing of electrons
chemical bonding
sharing of electrons
covalent bond
attraction of negatively and positively charged ions, more soluble and dissolves in water
ionic bonds
weak attraction between chains of ions that themselves are bonded by strong covalent/ionic bonds
van der waals bonds
attraction between metal atoms
metallic bonds
minerals that include silicon and oxygen
silicate
most abundant of the rock forming minerals
silicate
pyramidal shaped tetrahedron with relatively large oxygen ions at the corners and a small silicon ion in the center
silicate
silicon dioxide most abundant silicates in the crust of the earth fractures conchoidally colorless/clear harder than glass
quartz
aluminosilicates
60% of the crust
important in the ceramics and glass industries
feldspar
two major type of feldspar
alkali feldspar and plagioclase feldspar
silicates where si and o combine with fe and mg
not very resistant to weathering
tend to be altered/removed quickly
ferromagnesian minerals
three groups of fe-mg minerals
olivine
pyroxene
amphibole
formed from magma solidification
olivine
formed from pure fe-mg
pyroxene
double chained si-o tetrahedra
amphibole
minerals that contain the oxide anion O2 bonded to one or more metal ions
oxides
types of oxide:
Hematite
Bauxite
Magnetite
oxides that contains iron FE203
Hematite
Mixture of several aluminum oxides
Bauxite
oxygen des that Contains iron Fe304 and a natural magnet
Magnetite
Contains carbonate ions
Major constituent of limestone and marvles
Carbonates
minerals with a dominant halide
Sx: table salt(halite)
Halides
Minerals containin sulfur anion
Always associated with environmental degradation
Sulfides
Minerals containing sulfate ion within their structures
Sulfates
Minerals containing pgospate anion
Very few are common
Phosphate
Minerals formed of a single element (gold, copper, diamond)
Valuable
Found in mining
Native Element Minerals
The identification of minerals from patter recognition and testing for particular properties or characteristics of minerals
Physical Characteristics
Physical characteristic:
Color Streak Luster Density Hardness Cleavage Fracture
the perception when different wavelengths of visible light are incident upon the eye
Color
minerals that exhibit coloration that is directly related to its chemical composition
Idiochromatic minerals
minerals that exhibit coloration due to presence of an impurity, foreign element or a defect in it lattice structure
Allochromatic mineral
Color of a mineral subs when it has been ground to a fine powder
Streak
refers to the wayf of light is teflected
Luster
High rate of light absorption
Opaque
Permits passing of lights into it
Transparent
luster reflect light very poorly and dont shine
dull/earthly
luster possesses a sheen
Resinous
appears iridescent, opalescent
Pearly
luster appears to be covered with a thin layer of oil
Greasy
occurs whent light is reflected off of an aggregate of fine parallel fibers
Silky
luster occurs in minerals with predominant ionic binding and resembles the effective quality of a broken glass
Vitreous
luster are highly dispersive and transluscent, has a sparkling reflection of a diamond
Adamantine or brilliant
the level of difficulty with which a smooth surface of a ineral specimen may be scratched
Hardness
tendency of minerals to split along a definite structural planes, usually in planes where there are weaker bond strengths
Cleavage
Quality of cleavage:
Eminent Perfect Distinct Difficult Imperfect Indistinct
cleavage occuresnreadily; difficult to prevent from occuring
Eminent
Cleavage breaks easily, exposing continuous, flat surfaces which reflect light
Perfect
implies tgat cleavage surfaces are present, although they are marred by fractures or inperfections
Distinct
Occurs when mineral is split in a direction which doesnt serve as a plane of perfect or distinct cleavage
Fracture
Takes place aling a plane possessing difficult, indistinct, or non existing cleavage
Fracture
Types of fracture:
Choncoidal, irregular/uneven, hackly
results in a series of smoothly cyrved concentric rings about a stressed point, producing a shell-like appearance
Conchoidal fracture
Fractures in rough, rugged surface
uneven/irregular
describes a fractured surface with a multiple small, sharp and jagged irregularities
Hackly
