Final Review Flashcards
(139 cards)
1
Q
Steps for miller index by looking at plane:
A
- determine parameters, 2. invert parameters, 3. clear fractions
2
Q
What do { } mean for miller indices?
A
symmetrical equivalence of plane
3
Q
What do ( ) mean for miller indices?
A
single plane
4
Q
What do [ ] mean for miller indices?
A
single direction
5
Q
What do < > mean for miller indices?
A
symmetric equivalence, direction
6
Q
How do you know where a mineral last reached equilibrium given solvus diagram?
A
On solvus diagram, and given mineral info, you know temp last reached equilibrium by going to solvus line at percent of that mineral and drawing over to find temp
7
Q
What is the equation for diffusion coefficient?
A
D=l^2/t
8
Q
What is diffusion related to?
A
Diffusion is related to defect concentration
9
Q
At what temperature is diffusion favored? Why?
A
Diffusion favored at higher temps, more defects at higher temp, atoms vibrate faster, more likely to hop positions
10
Q
What diffuses faster: smaller or larger atoms?
A
smaller atoms
11
Q
Define diffusion
A
chemical transport through a medium
12
Q
Define liquidus:
A
line at which compositions of melt are at equilibrium with a crstalline phase
13
Q
Define solidus:
A
line at which compositions of crstalline phase are in equillibrium with the melt
14
Q
What mineral has a higher melting point on a phase diagram?
A
The one that turns to a melt at a higher temp, duh.
15
Q
Quartz formula
A
SiO2
16
Q
What category is quartz?
A
tectosilicate
17
Q
Kaolinite formula
A
Al2Si2O5(OH)4
18
Q
What category is kaolinite
A
phyllosilicate
19
Q
Olivine formula
A
(Mg,Fe)2SiO4
20
Q
What category is olivine?
A
nesosilicate
21
Q
Define polymerization
A
linking of SiO4 tetrahedra due to the O2- having the potential to bond to another silicon ion and entering into another tetrahedral group
22
Q
Nesosilicates/orthosilicates:
A
independent/isolated tetrahedra
23
Q
Sorosilicates/disilicates:
A
Si2O7, two SiO4 groups linked
24
Q
Cyclosilicates:
A
four-fold tetrahedra rings, Si4O12
25
Chain Silicates (inosilicates):
single, Si4O11, double Si8O22
26
Sheet silicates (phyllosilicates):
Si2O5, 3 oxygens of tetrahedra shared w/others
27
framework silicates (tectosilicates):
all four O shared, SiO2
28
radius ratio=
Rcation/Ranion
29
define coordination number:
the number anions in the polyhedron surrounding the cation
30
what does radius ratio dictate?
Dictates how many anions can fit snuggly around the cation
31
What is the rule for coordination and cations and anions?
cations must maintain contact with anions
32
What is the relationship between radius ratio and coordination number?
larger radius ratio=larger coordination number
33
What is the relationship between pressure and radius ratio?
With increased pressure, cation to anion increases, anions compressable
34
General formula of pyroxene
XYZ2O6
35
Possible M2 ions
Na+, Ca2+, Mn2+, Fe2+, Mg2+, Li+
36
Possible M1 ions
Mn2+, Fe2+, Mg2+, Fe3+, Al3+, Cr3+, Ti4+
37
Possilbe T ions
Si4+, Al3+
38
common pyroxenes
wollastonite, enstatite, ferrosilite, diopside, hedenbergite
39
wollastonite formula
CaSiO3
40
enstatite formula
MgSiO3
41
ferrosilite formula
FeSiO3
42
diposide formula
CaMgSi2O6
43
hedenbergite formula
CaFeSi2O6
44
bond strength=
ions valence chage/coordination number
45
relationship between bond strength and cleavage?
greater the bond strength, less likely to cleave
46
pyroxene cleavage angle
90ř
47
amphibole cleavage angle
120ř
48
is pyroxene a single or double chain silicate?
single
49
is amphibole a single or double chain silicate?
double
50
draw a pyroxene and amphibole with cleavage angles.
pg. 3
51
define dioctahedral
sheet structure in which each oxygen or (OH) group is only surrounded by two cations
52
define trioctahedral
sheet structure in which each oxygen or (OH) group is only surrounded by three cations
53
common cation for dioctahedral
Al
54
common cation for trioctahedral
Mg
55
What are the four tetrahedral, octahedral layering types?
TO; TOT; TOT+interlayer cation; TOT+brucite like sheet
56
Draw the four TO layering types
pg. 3
57
Example of TO layer
kaolinte
58
kaolinte formula
Al2Si2O5(OH)4
59
kaolinite di or tri
dioctahedral
60
TOT example
talc
61
talc formula
Mg3Si4O10(OH)2
62
talc di or tri
trioctahedral
63
TOT+interlayer cation example
muscovite
64
muscovite formula
KAl2(Si3Al)O10(OH)2
65
muscovite di or tri
dioctahedral
66
TOT+brucite like sheet example
chlorite
67
chlorite formula
(Mg,Fe)3(Si,Al)4O10(OH)2*(Mg,Fe)3(OH)6
68
chlorite di or tri
trioctahedral
69
Define exsolution:
Process whereby an initially homogenous solid solution separates into two (or possibly more) distinct crstalline minerals without addition or remove of material to or from system. (no change in bulk composition)
70
Define perthite:
texture, like in alkali feldspar system, exsolution lamellae approx. parallel to {100}. Coarse grained intergrowths consit of Na-rich feldspar lamellae exsolved from a K-rich host.
71
Si:O ratio pyroxenes
1Si:3O
72
Si:O ratio amphiboles:
4Si:11O
73
what is typically hydrated: pyroxenes or amphiboles?
amphiboles
74
What happens to water content during metamorphism? What is this generallly called?
Decreases, devolatization
75
Draw a diagram for pyroxenes
Pg. 4
76
Wollastonite formula
Ca2Si2O6
77
hedenburgite formula
CaFeSi2O6
78
Ferrosilite formula
Fe2Si2O6
79
Enstatite formula
Mg2Si2O6
80
diposide formula
CaMgSi2O6
81
amphibole diagram
Pg. 6
82
tremolite formula
Ca2Mg5Si8O22(OH)2
83
ferroactinolite formula
Ca2Fe5Si8O22(OH)2
84
grunerite formula
Fe7Si8O22(OH)2
85
cummingtonite-grunerite series formula
(Fe,Mg)7Si8O22(OH)2
86
anthophyllite series formula
(Mg,Fe)7Si8O22(OH)2
87
anthophyllite formula
Mg7Si8O22(OH)2
88
Si:O ratio nesosilicates
1Si:4O
89
what is a nesosilicate?
isolated tetrahedra
90
Si:O ratio sorosilicates
2Si:7O
91
What is a sorosilicate?
two tetrahedra connected in center
92
Si:O ratio cyclosilicates
1Si:3O
93
What is a cyclosilicate?
circle, 3 oxygens
94
Define solid solution
a minerals ability to allow extensive substitutions between certain elements among specific sites in the crystal structure and therefore has a variety of possible chemical compositions
95
Give an example of a solid solution mineral
olivine
96
olivine end members
forsterite, fayalite
97
forsterite formula
Mg2SiO4
98
fayalite formula
Fe2SiO4
99
Kyalnite, andalucite, sillimainte phase diagram
pg. 6
100
What does the presence of kyanite, andalucite, sillimanite indicate about metamorphism?
Indicates grade of metamorphism
101
Garnet general formula:
A3B2(Si3O12)
102
Garnet A sites:
cubic, contain large divalent cations (Ca, Fe, Mg, Mn)
103
Garnet B sites:
octahedral, smaller trivalent cations (Al, Fe)
104
Garnet groups
pyralspite, ugrandite
105
difference between garnet groups
pyralspite no Ca in A site, Al in B site; ugrandite Ca in A site
106
Si:O ratio tectosilicates
1Si:2O
107
Si:O ratio alkali feldspars
4(3Al,1Si):2O
108
Si:O ratio plagioclase feldspars
4(2Al,2Si):2O
109
define coupled substitution:
charge balance, less Al when a higher charged cation is subbed in
110
What are the two main feldspar solid solutions?
alkali feldspars, plagioclase feldspars
111
alkali feldspar formulae
KAlSi3O8 and NaAlSi3O8
112
plagioclase feldspar formula
NaAlSi3O8 and CaAl2Si3O8
113
feldspar end members
orthoclase, albite, anorthite
114
orthoclase formula
KAlSi3O8
115
albite formula
NaAlSi3O8
116
anorthite formula
CaAl2Si2O8
117
What conditions do feldspathoids form?
only form in melts with low SiO2
118
Feldspar diagram
Pg. 7
119
Si:O ratio micas
4Si:10O (1Al,3Si):10O
120
Si:O serpentine
2Si:5O
121
Si:O talc
4Si:10O
122
Si:O chlorite
4(Si,Al):10O
123
what makes something trioctahedral?
If substitution in octahedral layer is Mg2+ or Fe2+, the structure will be trioctaderal
124
What makes something dioctahedral?
If substitution in octahedral layer is Al3+, the structure will be dioctahedral
125
What is the reason something forms trioctahedral vs dioctahedral?
Due to a difference in charge. In trioctahedral, all octahedral sites are occupied, in dioctahedral strcutures, only 2/3 cation sites filled
126
Difference between clinopyroxenes and orthopyroxenes?
Clinopyroxenes contain Ca cation, orthopyroxenes do not
127
What do pyroxenes form?
blocky structures
128
What do amphiboles form?
rhombic structures
129
pyroxene cleavage angle
90
130
amphibole cleavage angle
120
131
Draw a sketch of nesosilicates
pg. 8
132
Draw a sketch of sorosilicates
pg. 8
133
draw a sketch of cyclosilicates
pg. 8
134
Draw a sketch of inosilicates
pg. 8
135
another word for inosilicates
chain silicates
136
Draw a sketch for phyllosilicates
pg. 8
137
Draw a sketch for tectosilicates
pg. 8
138
Relationship between cation charge and ionic radius. Why?
bigger cation charge = smaller ionic radius; less electrons, less electron-electron repulsion, smaller
139
What do hexagonal close pack and cubic close pack have in common?
Both 12 CN
