Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ES2002: Magma, Minerals And Metamorphism > Mineralogy > Flashcards

Mineralogy Flashcards

1
Q

What are the three natures of solid matter?

A

Crystalline
Amorphous
Glass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the structure of crystalline solid matter?

A

Atoms regularly ordered in three dimensions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the structure of glassy solid matter?

A

Atoms roughly the same distance apart and some areas with regular order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the structure of amorphous solid matter?

A

Truly randomly ordered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are crystalline solids so great/preferred?

A

Bond distances optimised
Bond angles optimised
Every atom in an optimum site
Everything in its place
=all energies minimised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why do crystalline minerals form?

A

Most energy efficient way to keep atoms together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do non crystalline solids form?

A

If you freeze melts or solutions fast they may not have time to crystallise and form non crystalline solids
Short range order
Entropy
Radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is devitrication?

A

The process of non crystalline solids reverting to crystalline forms over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is snowflake obsidian?

A

Where glass has been partially devitrified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a mineral?

A

A naturally occurring solid material usually crystalline with a chemical composition which is essentially constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a rock?

A

A naturally occurring aggregate of mineral grains which may include several different minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is glass a rock or mineral?

A

Considered as rocks since their compositions are very variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are crystals (structural wise)?

A

Ordered structures compromising of repeated stacking of single units in 3D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the individual building block of structure called?

A

Unit cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 7 crystal systems?

A

Cubic
Orthorhombic
Triclinic
Trigonal
Tetragonal
Monoclinic
Hexagonal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are two ways of determining the crystal system of an unknown mineral
?

A
  1. Consider shape and size of unit cell through X-ray diffraction
    2.; examine shape and symmetry of macroscopic crystals which reflects the symmetry of the unit cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the shape of a crystal defined?

A

Symmetry elements:
- 6/4/3/2 fold axis
- mirror plane
- centre of inversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the properties of a cubic crystal system?

A

X=y=z
A=B=Y=90
Properties the same in all directions=high symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the properties of a tetragonal crystal system?

A

X=y=z
A=B=Y=90
Properties the same in all directions=high symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the properties of an orthorhombic crystal system?

A

X!=y!=z
A=B=Y=90
Rectangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the properties of a monoclinic crystal system?

A

X!=y!=z
A!=g!=90, b=90

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the properties of a triclinic crystal system?

A

X!=y!=z
A!=b!=g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the groups of unit cells?

A
  1. Based on three principal axes (hexagonal and trigonal)
  2. Based on four principal axes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a gem?

A

Highly prized earth material, usually a mineral
Ie. Diamond, rubies, emerald

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the compositions of some precious minerals?

A

Diamond C
Rubies and sapphires Al2O3
Emerald and aquamarine Be3Al2(SiO3)6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are some precious ,metals?

A

Gold
Silver
Platinum
Electrum (alloy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the composition of some semi-precious minerals?

A

Amethyst, citrine, tigers eye = SiO2= quartz
Tanzanite = Ca2Al3(SiO4)(Si2O7)O(OH)=zoisite
Peridot = (Mg,Fe)2SiO4 = olivine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are some common non-mineral gems?

A

Amber = fossilised tree sap
Jet = coal
Pearls = biomineral of proteins and aragonite)
Lapis lazuli = rock of minerals lazurite, sodalite and calcite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What causes colour in gems?

A
  1. Small amount of transition metals
  2. Elements with hanging bonds
  3. Radiation damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Give an example of transition metals causing colour in gems.

A

Cr in Al2O3 makes red ruby
Fe and Ti in Al2O3 makes blue sapphire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is corundum?

A

Al2O3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is beryl?

A

Be3Al2(SiO3)6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Give an example of hanging bonds causing colour in gems.

A

N5+ replacing C4+ in diamond makes it yellow
B3+ replacing C4+ in a diamond makes it blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Give an example of radiation causing colour in gems.

A

Smoky colour in smoky quartz
Radiation damage + Fe makes amethyst purple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Are gems rare?

A

No
Particularly perfect forms of common minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the building block of earths crust?

A

Silicates
SiO4 tetrahedron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the properties of SiO2?

A

Silica SiO2
Chemically stable, doesn’t weather
Found in sedimentary rocks (ie sandstone), acidic igneous rocks (ie granite)

Macrocrystalline silica (quartz) vs crypto crystalline (chalcedony)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What can chalcedony be described as?

A

Jasper (red Fe3+)
Onyx (flat banding)
Agate (curved bands)
Flint (black, found in chalk)
Chert (blue layers in limestone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is disordered SiO2?

A

Opal
Disordered structure like a glass with irregular structure
Milky colour = opalescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the definition of a solid solution?

A

Mineral has a range of compositions (members of a solution) between fixed limits (end members)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the end members for olivine?

A

Forsterite Mg2SiO4
Fayalite Fe2SiO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are olivines important for?

A

Basalts/gabbros
Peridotite and dunite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the most common mineral in earths crust?

A

Feldspars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the composition of feldspars?

A

(Na, Ca, K)Al- 2 Si2- 3 O8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the end members of the feldspars?

A

K orthoclase
Na albite
Ca anorthite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are the solid solutions of feldspars?

A

Anorthite-albite = plagioclase feldspar
Albite-orthoclase = alkali feldspar
Mainly albite = ternary feldspar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is a complete and incomplete solid solution?

A

Complete= all combinations between end members is possible. Albite and orthoclase
Incomplete = gap in combinations. Orthoclase and anorthite

48
Q

What are the physical characteristics of feldspars?

A

Complex
Twinning
Exsolutin
Alteration

49
Q

What rock types are plagioclase feldspars found in?

A

Ultra basic rocks
Basic rocks
Intermediate rock

50
Q

What rock types are alkali feldspar found in?

A

Intermediate rocks
Acidic rocks
Alkaline rocks

51
Q

What are the end members of mica?

A

Biotite Mg Fe rich, dark colour
Muscovite Al rich, colourless

52
Q

What are the pyroxene end members?

A

Orthopyroxenes Mg Fe rich (no Ca)
Clinopyroxenes Ca

53
Q

What are pyroxenes characterised by?

A

Two prominent cleavages on basal sections that intersect at 90degrees

54
Q

What is the general formula for a pyroxene
?

A

X2+ +Y2+ [Si2O6]
Where X and Y are Ca. Mg, Fe, Na, Al

55
Q

What are the big ten rock forming minerals?

A

Calcite
Olivine
Pyroxene
Amphibole
Muscovite
Biotite
Anorthite
Albite
Orthoclase
Quartz

56
Q

What does bonding control?

A

Physical properties

57
Q

What are physical properties?

A

Hardness
Optical nature
Cleavage
Conductivity
Magnetivity

58
Q

What are the four types of bonding?

A

Ionic
Metallic
Covalent
Van der Waals

59
Q

What are positive nd negative ions called?

A

+ cations formed by elements with low ionisation potentials
- anions formed by elements with high electronegativity

60
Q

What are the properties of ionic bonding?

A

Sometimes soluble in water
Moderate hardness 3-5
Multiple perfect cleavages
High symmetry q

61
Q

What is metallic bonding?

A

Sea of delocalised electrons

62
Q

What are the properties of metallic bonds?

A

Moderately strong
Conductive
High symmetry
Malleability

63
Q

Where does covalent bonding occur?

A

Between elements of the same electronegativity or ionisation potential

64
Q

What are the properties of covalent bonds?

A

Strong
High hardness
Low symmetry
High refractive index

65
Q

What is van der waals bonding?

A

Caused by transient fluctuations in electron density

66
Q

What are the three Bravia’s lattices?

A

Primitive (corners) density =52%
Body centred 68%
Face centred 74%

Hexagonal close pack

67
Q

What do the dense structures of metals mean?

A

Bond distance is minimised
Solids with high density

68
Q

What it the tetrahedral arrangement of methane?

A

Bond angles are all 109.5
All bond distances are the same
Tetrahedral point symmetry

69
Q

What is the tetrahedral arrangement of SiO4?

A

All bond angles 109.5
Bond distances vary but are the same in one mineral
Cubic point symmetry

70
Q

What is the tetrahedral arrangement of CH3Cl?

A

Different electronegativity means different bond
HH-H bonds are 110
H-Cl angles 108
Distances are different
Trigonal point symmetry

71
Q

What happens if you change the identity of one element in SiO4?

A

Optimum bond angles move away from regular
Lower symmetry

72
Q

When does the SiO4 tetrahedral become distorted?

A

Ig you change 1 O for OH, F or Cl
Change central Si for Al
Place other ions nearby, changing local electron distribution density
Lower symmetry

73
Q

Give an example of a mineral that is triclinic?

74
Q

What are Goldschmidts rules?

A

Size matters
Charge matters

75
Q

What is an onuma diagram?

A

Show partition coefficient versus ionic radius
Shows the best size to fit in a structure

76
Q

Why does size matter?

A

Structures have sites that can accommodate ions of particular sizes
Optimum size is determined with an onuma diagram

77
Q

Why does charge matter?

A

Some ions are the wrong charge for the site
Al3+ can’t substitute for Mg2+

78
Q

Why do Mg and Fe substitute so much?

A

Roughly same size and charge

79
Q

What is an ideal solid solution?

A

Perfect complete solid solution with two or more ons exchanging for each other without distortion of the structure
Ie olivine

80
Q

How can the properties of members of an ideal solid solution be calculated?

A

From a linear combination of the properties of the end members (Vegards law)

81
Q

What can be calculated from the properties of end members?

A

Density
Refractive index
Unit cell parameters

82
Q

What is a limited solid solution?

A

When a solid solution forms to a certain degree but not completion

83
Q

What is homovalent substitution?

A

Swapping an ion of a particular charge with another of the same charge

84
Q

What defines a pyroxene?

A

X and Y site
Optimum radius 0.84 and 1 respectively
X can be Mg or Fe2+
Y can be Ca, Mg, Fe2+
Chain silicate

85
Q

What are the end members of pyroxenes?

A

X and Y site
Optimum radius 0.84 and 1 respectively
X can be Mg or Fe2+
Y can be Ca, Mg, Fe2+
Chain silicate

86
Q

What are Ca rich pyroxenes called?

A

Augite
End members diopside(mg) and hedenbergite (fe)

87
Q

How many sites can Ca occupy in a pyroxene?

A

1 Y site

2Ca = wollastonite=pyroxenoid

88
Q

What is the characteristics of pigeonite?

A

Breaks down over geological time to orthopyroxene and augite
Originally an Fe rich Magma with restricted stability

89
Q

What is aliovalent substitution?

A

The exchange of ions with different charges by counteracting the charge elsewhere

90
Q

Give examples of pyroxenes with aliovalent exchanges.

A

Jadeite: Na+ + Al3+ = Ca2+ + Mg2+
Aegirine: Na+ + Fe3+ = Ca2+ + Mg2+
Titanaugite: Ti4+ = Ca2+ + Mg2+

91
Q

Where are sodic pyroxenes found?

A

Mantle rocks (omphacite)
Collision zones (jadeite)
Alkaline igneous rocks (aegirine)

92
Q

What is the cleavage of pyroxenes?

A

90 degrees

93
Q

What is the structure of an amphibole?

A

Double chain
A X Y sites
A Y2 X5 (Si,Al)8 O22 (OH,F)2

94
Q

What are the optimum radii of amphiboles?

A

A = 1.3
Y = 1
X = 0.84

95
Q

What are the end members of amphiboles?

A

Orthoamphibole
Clinoamphibole

96
Q

What are the similarities between pyroxenes and amphiboles?

A

Mg and Fe solid solution is orthorhombic
Ca is monoclinic
Miscibility gap between Clino- and orthorhombic- forms
Sodic counterparts

97
Q

What do amphiboles have that pyroxenes dont?

A

Extra Na site which can accept Na or K
More sites=can take wider range of elements
Get octahedral and tetrahedral Al

98
Q

What is hornblende?

A

Amphibole equivalent of augite (Ca rich)

99
Q

What are sorosilicates?

A

Bow shaped silicates Si2O7
Epidote groups = low grade metamorphic Ca2Al3SiO4(OH)Si2O7
Zoisite = metamorphic marls
Allanite = accessory in igneous rocks

100
Q

What are cyclosilicates?

A

Ring silicates
Three fold axis = beitoite, catapleiite
Four fold axis = axinite
Six fold axis = beryl, cordierite
Nine-tetrahedral ring = eudialyte

101
Q

What are phyllosilicates?

A

Sheet silicates separated by sheets of ions
Silicate tetrahedral shares three corners
Ie clays

102
Q

What are clays?

A

Phyllosilicates
Mg = brucite layers = trioctahedral clays
Al = gibbsite layers = dioctahedral clays

103
Q

How are Clay minerals formed?

A

By stacking various permutations of aluminosilicate and octahedral layers

104
Q

What are the three groups of clays?

A

Kandites
Smectites
Illites

105
Q

What is a kandite clay?

A

1 octahedral : 1 aluminosilicate structure
Eg china clay - kaolinite

106
Q

What is smectite clay?

A

1 octahedral : 2 aluminosilicate structure
Eg montmorillonite
Inter layer gap where water and small ions can reside - clay swells in volume

107
Q

What are illite clays?

A

1 octahedral : 2 aluminosilicate structure +cation layer in between blocks

108
Q

What are mixed layer clays?

A

When many clay types are interfingered sequences of all three end members

109
Q

What causes desiccation cracks?

A

Caused by swelling and shrinkage of smectites

110
Q

Why does subsidence occur?

A

Building on clay-rich sediments will subside in drought or if too much water is abstracted from subsurface aquifers

111
Q

What are clays regulators of?

A

Subsurface water composition as smectites allow the exchange of cations with water

112
Q

What do clays do with ions transported by water?

A

Adsorption occurs, acculmalating pollutions
Can be reversed by pH change

113
Q

How do you identify clays?

A

By Secondary Electron Microscope - different morphologies
By X Ray Diffraction

114
Q

How can you identify a smectite with XRD

A

Have different patterns when wet vs dry

ES2002: Magma, Minerals And Metamorphism (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions