Chapter-3 Mineralogy

Question 1

are naturally occurring, solid earth materials formed by geologic processes.

Answer 1

Minerals

Question 2

– is composed of atom, the smallest part of a chemical element that can take part in a chemical reaction or combine with another atom.

Answer 2

All matter- including rocks, minerals, water etc.

Question 3

are atoms of the same (atomic number) with different neutrons in the nucleus (variable atomic mass number)

Answer 3

Isotopes

Question 4

Isotopes that are unstable and undergo nuclear decay (spontaneously change and emit nuclear radiation) are called

Answer 4

Radioisotopes

Question 5

A mineral is formally defined as an element or a chemical compound that must:

Answer 5

1. Be naturally-formed. (Excludes human-made diamonds)
   
   2. Normally be a solid. (Excludes fluids)
   3. Have a characteristic chemical formula
   4. Have a characteristic crystalline structure

Question 6

substance composed of two or more elements that can be represented by a chemical formula

Answer 6

Compounds

note:Minerals can either be elements or compounds

Question 7

Mineral Indetification

Answer 7

Chemical Composition

Physical Characteristics

Question 8

attraction between atoms, sharing of electrons or both

Answer 8

Chemical bond

Question 9

sharing of electrons (diamond)

Answer 9

Covalent bond

Question 10

attraction of negatively and positively charged ions, more soluble, dissolves usually in water (halite, Na+, Cl-)

Answer 10

Ionic bond

Question 11

weak attraction between chains of ions that themselves are bonded by stronger covalent/ionic bonds (graphite)

Answer 11

Van der Waals bond

Question 12

– attraction between metal atoms (gold)

Answer 12

Metallic bond

Question 13

Minerals that include the elements silicon Si and oxygen O in their chemical composition
Most abundant of the rock-forming minerals

Answer 13

Silicates

Question 14

Form of silicon dioxide SiO2, one of the most abundant silicates in the crust of the earth
Fractures conchoidally (similar to shells)
Colorless/clear, some may contain impurities
Harder than glass

Answer 14

Quartz

Question 15

are aluminosilicates, containing Si, O, Al, in combination with K, Na or Ca in a network of Si-O tetrahedra
Constituting 60% of the crust
Commercially important in the ceramics and glass industries

Answer 15

Feldspars

Question 16

2 major types of Feldspars

Answer 16

Alkali feldspar (contains K) and Plagioclase feldspar (contains Na or Ca)

Question 17

-minerals are group of silicates where Si and O combine with Fe and Mg.
Not very resistant to weathering, they tend to be altered or removed from their location relatively quickly.

Answer 17

Ferromanganesian Minerals

Question 18

Three groups of Fe-Mg minerals:

Answer 18

Olivine – formed from magma solidification
Pyroxene – formed from pure Fe-Mg substituting for each other
Amphibole – double-chained Si-O tetrahedra

Question 19

are minerals that contain the oxide anion O2- bonded to one or more metal ions.

Answer 19

Oxides

Question 20

Types of oxides:

Answer 20

Hematite – contains iron Fe2O3
Bauxite – mixture of several aluminum oxides
Magnetite – contains iron Fe3O4 and a natural magnet

Question 21

Contains the carbonate ion CO3,2-

Major constituent of limestone and marbles.

Answer 21

Carbonates

Question 22

are minerals with a dominant halide (halogens, Group 17) anions F-, Cl-, Br-, I-

Answer 22

Halides

Question 23

Most common halide is ?

Answer 23

Table Salt (NaCl) also known as halite

Question 24

Minerals containing sulfur anion S2-

Always associated with environmental degradation.

Answer 24

Sulfides

Question 25

Minerals containing the sulfate ion (SO4,2-) within their structures

Answer 25

Sulfates

Question 26

Minerals containing phosphate anion (PO4,3-) along with vanadate, arsenate, chorine, fluorine and hydroxide anions

Answer 26

Phosphates

Question 27

Minerals formed of a single element, such as gold, silver, copper, diamond (carbon) They have long been sought as valuable minerals

Answer 27

Native Element Minerals

Question 28

Physical Characteristics of a minerals are identified through?

Answer 28

``` Color Streak Luster Density Hardness Cleavage Fracture ```

Question 29

is the perception when different wavelengths of visible light are incident upon the eye.

Answer 29

Color

Question 30

are minerals that exhibit coloration that is directly related to its chemical composition

Answer 30

Idiochromatic Minerals

Question 31

are minerals that exhibit coloration due to presence of an impurity, foreign element or a defect in its lattice structure

Answer 31

Allochromatic Minerals

Question 32

is the color of a mineral substance when it has been ground to a fine powder

Answer 32

Streak

Question 33

refers to the way light is reflected from the mineral.

Answer 33

Luster

Question 34

Two types of Luster:

Answer 34

Opaque has high rate of light absorption (20-50% reflection of incident light) Transparent permits passing of lights into it (5-20% reflection of incident light)

Question 35

Two categories of mineral luster:

Answer 35

Metallic and Nonmetallic

Question 36

reflect light very poorly and do not shine.

Answer 36

Dull/earthy Luster

Question 37

possesses a sheen resembling that of resin, with refractive index greater than 2.0

Answer 37

Reisnous Luster

Question 38

appears iridescent, opalescent or pearly

Answer 38

Pearly Luster

Question 39

appears to be covered with a thin layer of oil

Answer 39

Greasy Luster

Question 40

occurs when light is reflected off of an aggregate of fine parallel fibers

Answer 40

Silky Luster

Question 41

occurs in minerals with predominant ionic bonding and resembles the reflective quality of a broken glass

Answer 41

Vitreous Luster

Question 42

are highly dispersive and translucent, has a sparkling reflection of diamond

Answer 42

Adamantine or Brilliant Luster

Question 43

is the level of difficulty with which a smooth surface of a mineral specimen may be scratched.

Answer 43

Hardness

Question 44

is the tendency of minerals to split along a definite structural planes, usually in planes where there are weaker bond strengths

Answer 44

Cleavage

Question 45

Quality of a cleavage:

Answer 45

``` Eminent Perfect Distinct Difficult Imperfect Indistinct ```

Question 46

cleavage occurs readily; difficult to prevent from occurring

Answer 46

Eminent

Question 47

– cleavage breaks easily, exposing continuous, flat surfaces which reflect light

Answer 47

Perfect

Question 48

implies that cleavage surfaces are present, although they are marred by fractures or imperfections

Answer 48

Distinct

Question 49

occurs when a mineral is split in a direction which does not serve as a plane of perfect or distinct cleavage

Answer 49

Fracture

Question 50

Types of fractures:

Answer 50

Conchoidal Irregular/uneven Hackly

Question 51

results in a series of smoothly curved concentric rings about a stressed point, producing a shell-like appearance

Answer 51

Conchoidal Fracture

Question 52

fracture results in a rough, rugged surface

Answer 52

Irregular/Uneven Fracture

Question 53

describes a fractured surface with multiple small, sharp and jagged irregularities.

Answer 53

Hackly Fracture