MINERALOGY BASIC CONCEPTS (GEOCHEM OF MINERALS) Flashcards
1
Q
Differentiate Monomineralic from Polyminerallic rock?
A
Naturally occuring,
Inorganic,
Homogenous solid
Defined chemical composition,
Orderly Cyrstal Structure, Solid
2
Q
Basic pattern of atoms
A
Motif
3
Q
long range pattern of atom characteristic of each mineral species
A
Crystal structure
4
Q
Materials that possess geometric crystal structure
A
Crystalline
5
Q
A solid material that lacks long range crystal structue
A
amorphous
6
Q
Naturally ocuring solid which lack unique combination of crystal sturcture and chemical composition
A
Mineraloid
7
Q
Examples of mineraloids
A
Volcanic Glass and Coal
8
Q
What is a rock?
A
Aggregare of minerals crystals, and/or mineraloids
9
Q
Differentiate Monomineralic from Polyminerallic rock?
A
A monomineralic is composed of cyrstals of a single minerals like quartzite, quartz sandstone and dunite (Purely OLivine) while polyminerallic are composed of many types of mineral crystals
10
Q
How many m is 1 angstrom?
A
10^-10
11
Q
1 amu (atomic mass unit or dalton) is how much in kg
A
1.661*10^-27
12
Q
What’s the equivalent of 1amu?
A
1/12 mass of carbon atom
13
Q
Mass of P, N and E?
A
P 1.000728 amu ,
N 1.000867 amu,
E 0.0000054 amu
14
Q
No. of Protons which distinguishes atom of one element from that of another
A
Nucleus (Z,lower left)
15
Q
What is the highest atomic number for naturally occuring elements?
A
Z=92, Uranium
16
Q
No of Protons and Neutrons normally written at the upper left of the element
A
atomic mass
17
Q
atomic mass of Oxygen
A
16 amu
18
Q
Atoms of the same element which possess different atomic mass number?
A
Isotopes
19
Q
H isotope with 0 neutron?
A
Protium 1H
20
Q
H isotope with 2 atomic mass number (1neutron)?
A
Deuterium 2H
21
Q
H isotope with 3 atomic mass number (2 neutron)?
A
Tritium 3H
22
Q
Isotopes of oxygen?
A
16,17,18
23
Q
Average atomic mass of an element?
A
Weighted average for all the isotopes
(e.g: O16, O17, O18)
24
Q
Differentiate Stable Isotopes and Radioactive isotopes?
A
Stable isotopes have stable nuclei and remain unchanged which means they retains same number of protons and neutrons over time, on the other hand, Radioactive isotopes have unstable nuclear configuration w/c changes overtime via decay processes
25
3D configuration or shapes of electron clouds
Orbitals
26
This siginifies the principal quantum energy level or shell in which a particular electron occurs usually numbered from 1-7
Principal quantum number (n)
27
This signify the directional quantum energy region or subshell in which electron occurs usually labeled s,p,d,f
Azimuthal quantum number
28
Whats the max electron for S,P,D,F (by 4s)
2,6,10,14
29
Stable Octet
S2, P6 electron configuration
30
Elements with completely filled shells and S-andPshells that have very stable electron configuration
Helium
Neon
Argon
Krypton
31
Tables which attempt to portray the periodic behavior of elements
Periodic table of elements
32
What do the numbers on the left side of the table represents
Rows/Periods Numbers 1-7- indicate highest Principle Quantum Level (Energy level of the valence electrons of elements in that row) or the highest ground state quantum level
33
How are elements classified in each row?
Their position depends on the distribution of electrons w/in principal quantum levels
34
HOw are elements classified into columns/group?
By their tendency to lose or gain electrons forming positive or negative charged ions
35
electrically charge atoms?
ions
36
process by which atoms acquire charge?
ionization
37
The amount of energy required to remove an electron from its electron cloud
Ionization Energy (kjoules/mole)
38
Elemetns which relatively low first ionization energy and tend to lose one or more electrons
Electropositive Elements
39
Elements which high first ionization energy
Electronegative Elements
40
positivey charged ions in which P>e, they lose electrons and their charhe s equal to the number of excess proton P-e
Cation
41
Negatively chaged ion that has a charge equal to the umber of excess electron, gains electron
Anion
42
Compare and contrast ionization energies of Metallic and nonmetallic elements
Metallic elements have low ionization energy electronpositive elements and thus tend to give up one or more weakly held electrons while NonMetallic elements have high first ionization energy electronegative elements and thus tend to absorn loosely bound electrons
43
Metallic
Low first Ionization Energy (Madaling Bumitaw) (<900 kJ/mol)electropositive
44
Non Metallic
High first Ionization Energy (Linta ayaw Bumitaw) (>900 kL/mol), Have high electron affinity and tend to be electronegative
45
These are monovalent cations due to low first ionization energy tend to lose 1 electron to be stable
1 (IA)
46
These are divalent cations tend to lose 2 electron
2 (IIA)
47
These elements lose variable number of electrons depending upon the environments
Transition elements 3-12 (IIIB-IIB)
(8-10, VIIIB)
48
Elements which lose three electrons
13 (IIIA)
49
Elements which lose four electron or small number of electrons
14 (IVA)
50
Elements which lose five electrons or capture 3 electrons
15 (VA)
51
Gain two electrons or six in some environments
16 (VIA)
52
Gain 1 electrons
17 (VIIA)
53
Stable electron configuration
18 (VIIIA)
54
Elements in the middle of the periodic table are chracterized by
Electropositive
tend to lose various numbers of electrons to become ccations
55
This is the half distance between the nuclei of bonded identical neighboring atoms
Atomic Radii
56
Whats the trend of atomic radii in columns and rows?
1-7 increading from top to bottom, decreases from left to right
57
These are electrons in the outermost shell which are the least bound to the nucleaous and are usually involved in wide variety of chemical reactions especially in ionization processes
Valence Electrons
58
When atoms are charged their radius becomes?
Ionic radii
59
Relationship of charge of cations an its radii?
higher the charge smaller the radius
60
ralationship of charge of anion and its effective radii?
higher the charge the larger the radius
61
Sodium
1.86 A
62
Calcium
1.97 A
63
Aluminum
1.46 A
64
Silicon
1.18 A
65
Iron
1.23 A
66
Nitrogen
0.75 A
67
Oxygen
0.73 A
68
Flourine
0.72 A
69
forces which held together atoms in minerals and rocks and strongly influence the properties and behavior of minerals, rocks, and other Earth materials
Chemical bonds
70
Bonds which links together metallic and non metallic elements?
Ionic or electrostatic
71
non metallic to non metallic bonds
Covalent bonds
72
Metallic to metallic bonds
Metallic bonds
73
This is an empirical measure of the tendency of an element to attract electrons when atoms bonds
Electronegativity (En)
74
The measure of energy released when an electron is added to an unbound atom
Electron Affinity
75
Energy required to remove an electron from an ion
Ionization energy
76
This happens when very metallic atoms bond with very non-metallic atoms by Metallic atoms give up or donate their valence electrons to non metallic atoms
Electrostatic bond or ionic bonds
77
What columns in the periodic table are very metallic atoms and tend to be cations
Columns 1 and 2
78
What columns in the periodic table are very non metallic and tend to be anion
Columns 16 an 17
79
Ionic pairs in the periodic table
IA and VII A, IIA and VIA
80
What are the properties of crystal with ionic bond?
Variable hardness, Brittle, quite solube in polar substances, intermediate melting temp, transparent to transluscent minerals with light colors and virteous to sub-vitreous luster
81
When non-metallic atoms bond with non metallic atoms and share electrons?
Covalent Bonds
82
diatomic gases with covalent bonding
O, Cl, F, I, N
83
Mineral with covalent bonding
Diamond
84
What column is carbon and its implication?
Column 14 IVA, C tends to absorb or donate 4 electrons
85
Properties of covalently bonded minerals?
Hard and brittle, insoluble in water, crystallize from metls, moderate to high melting temp, tranparent to translucent with vitreous, subvitreous and adamantine lusters
86
Bonding of metallic to metallic atoms which is usally protrayed as positivelt chargen atoms in a matrix of delocalized valance electrons and are only temporarily associated with individual atoms
Metallic
87
Properties of Minerals with metallic bond
failrly soft and moderately hard, plastic, malleable and ductile, excellent electrical and thermal condctors, frequently high SG, excellent absrobers and refletors of light commonly opaque with metallic luster
88
The difference between the electronegativities of two elements sharing the bond
Electronegativity difference
89
When does transitional bond become dominantly ionic or dominantly covalent?
<1.68 En.D. dominantly covalent,
>1.68 En.D. dominantly ionic
90
Mineral which have a transitional bond of ionic-metallic which gives it brittle and soluble property and soft, opaque and metallic luster dominantly metallic?
Galena (PbS)
91
Mineral which have a transitional bond between metallic and covalent?
Pyrite
92
What type of hybrid is Silica minerals?
Covalent-Ionic (En: 1.54) dominantly covalent
93
Minerals which have a transional ionic-covalent but are dominantly ionic?
Halite
94
Bond which is caused by weak electric dipole forces which are caused by assymetrical distribution of electrons in the electron cloud
Van der waals
95
Characteristic of Van de Waals bonding
Very weak and soft like
Talc and graphite
96
A bond which exists between hyrdogen or hydroxyl ion and an electronegative ion and is relatively weak which occur in hydrated or hydroxyl minerals
Hydrogen bonds
97
These are rules describing anion-cation relationships in ionically bonded substancs
Pauling's Rule
98
Who established these rules?
Linus Paulings 1929
99
What is Rule #1?
1.1 The distance between anion and cation in a polyhedron is the sum of their radii (Radium Sum)
1.2 the number of coordinated anions is determined by cation:anion ratio
100
What is Rule#2?
Elecrostatic valency rule
When the sum of the strength of the bonds that join cation and anion in the polyhedron is equals to the charge on the cation and anion, then the ionic structure is stable
101
What is Rule #3?
Sharing of edges and particularly faces of adjacent anions decreases the stability of an ionic structure since similar charges tend to repel. Ajdacent polyhedra tend to share corners rather than edges
102
What is Rule#4?
Cations with high valence electrons and small cooridnation number tend not to share polyhedral elements since their charges tend to repel
103
What is Rule#5?
Rule of Parsimony - the number of different cations and anions in a crystal structure tends to be small
104
Coordination Polyhedra
the basic unit of Crystal Structure which are Clusters of atoms or ions bonded together to other coordinating atoms
and that Creates a link between crystal structure and crystal chemistry
105
Cordination Number
The number of nearest neighbor ions or atoms on which the depended on the Radius Ratio
106
What is Radius Ratio RR?
Rc/Ra
107
Caveats of predicting CN using RR
1) Increasnig effective Ionic Radius means increasing CN
2) the more a bond becomes covalent or polaried, RR becomes ineffective to predict CN
3) RR is not applicable to Metallic Bonds
108
Peaks of RR
0.155 0.225 0.414 0.732 1.00
109
If the RR <0.155 what is CN and the Coordination Polyhedra?
2, Line
110
If RR is 0.155-0.225, what is CN and coordination polyhedra?
3, Triangle
111
If RR is 0.255-0.414, what is CN and coordination polyhedra?
4, Tetrahedron
112
If RR is 0.414-0.732 what is CN and CP?
6, Octahedron
113
If RR is 0.732 - 1.00 what is CN an CP?
8, Cube
114
if RR is >1.00, what is CN and CP?
12, cubeoctahedron complex
115
Concept of Electrostatic Valency
EV evokes that the charge of a cation and anion is balanced by the electrostatic charge compensating of the bonds between them. Formula is EV= Z (Charge)/CN
116
EV formulaz
EV=Z / CN
117
The most common minerals in the Earth's crust and upper mantle
Silicates
118
Native Elemen
none
119
Halides
F-1, Cl-1, Br-1
120
Sulfides
S-2, S-4
121
Arsenides
As-2, As-3
122
Sulfarsenides
As-2, As-3 and S-2 or S-4
123
Selenides
Se-2
124
Tellurides
Te-2
125
Oxides
O-2
126
Hydroxides
(OH)-1
127
Carbonates
(CO3)-2
128
Nitrates
(NO3)-1
129
Borates
(BO3)-3 and (BO4)-5
130
Sulfates
(SO4)-2
131
Phosphates
(PO4)-3
132
Chromates
(CrO4)-5
133
Arsenates
(AsO4)-3
134
Vandates
(VO4)-3
135
Molybdates
(MoO4)-2
136
Tungstates
(WO4)-2
137
Silicates
(SiO4)-4
138
Silica
No of shared Oxygen Ions
139
Nesosilicates
0
140
Sorosilicates
1
141
Cyclosilicates
2
142
Inosilicates Single Chain
2
143
Inosilicates Double Chain
2-3 alternately
144
Phyllosilicates
3
145
Tectosilicates
4
146
Substitution is favored when radius difference is within this range at Normal Surface Temp
10-15%
147
When cation radii exceed this mark, cation substitution becomes negligible
30%
148
when can Larger difference in radius be possible in cationic substitution
at higher temps
149
when does two or more substitution happen?
When there are multple coordination sites
150
Favorable Conditios for subtitutions
1) Same Ionic Radii or small differnce
2) Same Charge or can be different charge if there are multiple site
3) Ions are widely available in the environment at which the mineral is growing
151
This exist when two or more ions of similar radius and charge substitute for one another in a coordination site in any proportion
Simple Complete Substitution
152
Mg ionic radius
0.66 Angstroms
153
Fe ionic Radius
0.74 Angstroms
154
When two end members can substitute for one another in any proportion this solid solution exists
Complete Solid Solution Series
155
a line which can represent two component solid soln series
Tie Line
156
Three end members of pure carbonates
siderite, Magnesite and Rhodocrosite
157
Involves Simultaneous substitution of ions of different charges in two different structureal sites that preserves electric neutrality of the crystal lattice
Coupled Ionic Subtitution
158
Best example for Coupled Ionic Substitution
Plagioclase
159
Whats different in Na and Ca
Charge Na+1 Ca+2
160
What neutralized the charge imbalance caused by the substitution of Na+1 and Ca+2?
Substitution of Al+3 and Si+4
161
What ions are in tandem during ionic couples subsitution
(Na+1 and Si+4)
(Ca+2 and Al+3)
162
General Chemical Formular for Plag
(Na,Ca)(Si,Al) AlSi2O8
163
Pure Sodium Plag
Albite (NaAlSi3O8)
164
Pure Calcium Plag
Anorthite (CaAl2Si2O8)
165
In a tie line where does albite and anorthite positioned
Left end and right end respectively
166
A substitution involving ions of substantially different size that limits the amount of substitution between end members
Limited Solid Solution
167
examples of Limites Solid Soln
Magnesite and Calcite
168
Gaps in solid solutions which represents potential compositions that do not exist in nature due to limited substituition
Miscibility Gaps
169
Miscibility Gap between Clacite Magnesite Tie Line
Ct75Ms25 to Ct60Ms40
60-75% Ca
25-45% Mg
170
Low Mg Calcite
Less than 4% Mg >96% Ca
171
High Mg Clacite
4-25% Mg (Ct75-96 and Ms4-25)
75-96% Ca
172
Carbonates with composition Ms40-55 and Cs45-60
Dolomite (40-55% Mg, 45-60% Ca)
