Gly1000 Exam 1 Study Guide
Minerals
Eight most abundant elements in the Earth’s Crust:
Abundance % by weight –
Most common Ionic Form
Most Common Coordination Numbers
Relative Ionic Size
Oxygen (O)
46.6 %
O-2
- - -
1.40
Silicon (Si)
27.7 %
Si+4
Si (4)
0.26
Aluminum (Al)
8.1 %
Al+3
Al (4, or 6)
0.39
Iron (Fe)
5.0 %
Fe+2
Fe (6)
0.63
Calcium (Ca)
3.6 %
Ca+2
Ca (8)
1.00
Sodium (Na)
2.8 %
Na+1
Na (8)
0.99
Potassium (K)
2.6 %
K+1
K (8, 12)
1.37
Magnesium (Mg)
2.1 %
Mg+2
- - -
0.72
Distinction between crystalline and non-crystalline solids
Crystalline – term refers to the ordered, symmetrical, arrangement or the atoms that make up the structure
Minerals are naturally occurring solid chemical compounds with crystalline structure
Exhibits cleavage
Non-Crystalline – (Ex. Glass) Soften as the temperature increases and have no sharply defined melting point
The Most common silicate minerals: Structure and Composition
Olivine - (Mg, Fe)2SiO4 ; Independent Tetrahedral
Pyroxenes – (Mg, Fe)2Si2O6) ; Single Chain
Amphiboles – (W,X, Al)7-8(Z4O11)2(OH)2 ; double chains
Biotite mica – K(MgFe)3(AlSi3O10)(OH)2 ; Sheet silicates
Muscovite mica – KAl2(AlSi3O10)(OH)2 ; Sheet Silicates
Plagioclase feldspar – NaAlSi3O8 --- CaAl2Si2O8 (solid solution series) ; framework silicates
Alkali Feldspars – KalSi3O8 –CaAl2Si2O8 (solid solution series); Framework silicates
Quartz – SiO2 ; Framework Silicates
W represents the large cations Ca, Na and K (That can substitute for one another)
X Represents the smaller Mg and Fe
Z Represents the cations in the tetrahedral sites, Si and Al
Pairs of elements that commonly substitute for one another in Silicates:
Si and Al
Mg and Fe (and also Al)
Na and K
Na and Ca
Factors that control substitution:
The size of the ions and the size of the crystallographic sites into which they substitute
The charges on the ions that are substitution for one another – if charges are the same, then the crystal structure can remain electrically neutral; if charges not the same then other
Eight most abundant elements in the Earth’s Crust:
Abundance % by weight –
Most common Ionic Form
Most Common Coordination Numbers
Relative Ionic Size
Oxygen (O)
46.6 %
O-2
- - -
1.40
Silicon (Si)
27.7 %
Si+4
Si (4)
0.26
Aluminum (Al)
8.1 %
Al+3
Al (4, or 6)
0.39
Iron (Fe)
5.0 %
Fe+2
Fe (6)
0.63
Calcium (Ca)
3.6 %
Ca+2
Ca (8)
1.00
Sodium (Na)
2.8 %
Na+1
Na (8)
0.99
Potassium (K)
2.6 %
K+1
K (8, 12)
1.37
Magnesium (Mg)
2.1 %
Mg+2
- - -
0.72
Distinction between crystalline and non-crystalline solids
Crystalline – term refers to the ordered, symmetrical, arrangement or the atoms that make up the structure
Minerals are naturally occurring solid chemical compounds with crystalline structure
Exhibits cleavage
Non-Crystalline – (Ex. Glass) Soften as the temperature increases and have no sharply defined melting point
The Most common silicate minerals: Structure and Composition
Olivine - (Mg, Fe)2SiO4 ; Independent Tetrahedral
Pyroxenes – (Mg, Fe)2Si2O6) ; Single Chain
Amphiboles – (W,X, Al)7-8(Z4O11)2(OH)2 ; double chains
Biotite mica – K(MgFe)3(AlSi3O10)(OH)2 ; Sheet silicates
Muscovite mica – KAl2(AlSi3O10)(OH)2 ; Sheet Silicates
Plagioclase feldspar – NaAlSi3O8 --- CaAl2Si2O8 (solid solution series) ; framework silicates
Alkali Feldspars – KalSi3O8 –CaAl2Si2O8 (solid solution series); Framework silicates
Quartz – SiO2 ; Framework Silicates
W represents the large cations Ca, Na and K (That can substitute for one another)
X Represents the smaller Mg and Fe
Z Represents the cations in the tetrahedral sites, Si and Al
Pairs of elements that commonly substitute for one another in Silicates:
Si and Al
Mg and Fe (and also Al)
Na and K
Na and Ca
Factors that control substitution:
The size of the ions and the size of the crystallographic sites into which they substitute
The charges on the ions that are substitution for one another – if charges are the same, then the crystal structure can remain electrically neutral; if charges not the same then other