ASBOG FG Review Mineralogy and
Petrology Exam-Graded A
Definition of a Mineral - ANS-1. naturally occurring
2. Inorganic
3. solid
4. Definite chemical composition
5. Defined Crystalline structure
Shape of Silicate Minerals - ANS-tetrahedron with four large oxygen atoms surrounding
a silicon atom
Neosilicates - ANS-SiO4; composed of a single tetrahedral; includes zircon, olivine, and
garnet
Sorosilicates - ANS-Si2O7; isolated double or linked tetrahedral; inlcudes lawsonite,
and hemimorphrite
cyclosilicates - ANS-SiO3; tetrahedral ring formed (cyclo); includes beryl group and
tourmaline
inosilicates (single chain) - ANS-SiO3; includes pyroxene group and pyroxenoid group
inosilicates (double chain) - ANS-Si4O11; includes amphibole group
phyllosilicates - ANS-Si2O5; forms sheets; includes biotite, talc, and chlorite
tectosilicates - ANS-SiO2 and Si3O8; forms frameworks; includes feldspar and zeolite
groups
Are intrusive igneous rocks coarse or fine grained - ANS-coarse (cooled slower)
Are extrusive igneous rocks coarse or fine grained - ANS-fine (cooled faster)
hypabyssal rocks are formed where? - ANS-just below the earths surface
phaneritic igneous texture - ANS-crystal structure can be seen with the naked eye
(igneous)
aphanitic igneous texture - ANS-crystal structure cannot be seen with naked eye
(extrusive)
, Bowen's Reaction Series discontinuous reaction - ANS-left side: first to form (top) last to
form (bottom)
1. Olivine
2. Mg Pyroxene
3. Mg-Ca pyroxene
4. Amphibole
5. Biotite
6. Potassium Feldspar
7. Muscovite
8. Quartz
Bowen's Reaction Series continuous reaction - ANS-right side: first to form (top) last to
form (bottom)
1. Anorthite
2. Labradorite
3. Andesite
4. Oligoclase
5. Albite
6. Potassium Feldspar
7. Muscovite
8. Quartz
In Bowen's Reaction Series, the more stable minerals are where, and the least stable
minerals are where? - ANS-The least stable and most susceptible to weathering are at
the top, while the most stable are at the bottom (quartz)
Detrital Sedimentary Rocks - ANS-made from broken fragments of other rocks derived
from erosion
chemical and biochemical sedimentary rocks - ANS-made up of precipitated minerals
diagenetic sedimentary rocks - ANS-recrystallization, replacement, or other chemical
modification of sediments - dolomite, chert
Sedimentary rocks form how much of the crust? How much of the surface? - ANS-Less
than 10% of the crust, and 75% of the continental surface
95% of sedimentary rocks are what? - ANS-sandstones, mudrocks, and carbonate
rocks
Mudrocks make up how much of all sedimentary rocks - ANS-65%
Sandstones make up how much of all sedimentary rocks - ANS-20 to 25%
Carbonate Rocks make up how much of all sedimentary rocks - ANS-10 to 15%
Petrology Exam-Graded A
Definition of a Mineral - ANS-1. naturally occurring
2. Inorganic
3. solid
4. Definite chemical composition
5. Defined Crystalline structure
Shape of Silicate Minerals - ANS-tetrahedron with four large oxygen atoms surrounding
a silicon atom
Neosilicates - ANS-SiO4; composed of a single tetrahedral; includes zircon, olivine, and
garnet
Sorosilicates - ANS-Si2O7; isolated double or linked tetrahedral; inlcudes lawsonite,
and hemimorphrite
cyclosilicates - ANS-SiO3; tetrahedral ring formed (cyclo); includes beryl group and
tourmaline
inosilicates (single chain) - ANS-SiO3; includes pyroxene group and pyroxenoid group
inosilicates (double chain) - ANS-Si4O11; includes amphibole group
phyllosilicates - ANS-Si2O5; forms sheets; includes biotite, talc, and chlorite
tectosilicates - ANS-SiO2 and Si3O8; forms frameworks; includes feldspar and zeolite
groups
Are intrusive igneous rocks coarse or fine grained - ANS-coarse (cooled slower)
Are extrusive igneous rocks coarse or fine grained - ANS-fine (cooled faster)
hypabyssal rocks are formed where? - ANS-just below the earths surface
phaneritic igneous texture - ANS-crystal structure can be seen with the naked eye
(igneous)
aphanitic igneous texture - ANS-crystal structure cannot be seen with naked eye
(extrusive)
, Bowen's Reaction Series discontinuous reaction - ANS-left side: first to form (top) last to
form (bottom)
1. Olivine
2. Mg Pyroxene
3. Mg-Ca pyroxene
4. Amphibole
5. Biotite
6. Potassium Feldspar
7. Muscovite
8. Quartz
Bowen's Reaction Series continuous reaction - ANS-right side: first to form (top) last to
form (bottom)
1. Anorthite
2. Labradorite
3. Andesite
4. Oligoclase
5. Albite
6. Potassium Feldspar
7. Muscovite
8. Quartz
In Bowen's Reaction Series, the more stable minerals are where, and the least stable
minerals are where? - ANS-The least stable and most susceptible to weathering are at
the top, while the most stable are at the bottom (quartz)
Detrital Sedimentary Rocks - ANS-made from broken fragments of other rocks derived
from erosion
chemical and biochemical sedimentary rocks - ANS-made up of precipitated minerals
diagenetic sedimentary rocks - ANS-recrystallization, replacement, or other chemical
modification of sediments - dolomite, chert
Sedimentary rocks form how much of the crust? How much of the surface? - ANS-Less
than 10% of the crust, and 75% of the continental surface
95% of sedimentary rocks are what? - ANS-sandstones, mudrocks, and carbonate
rocks
Mudrocks make up how much of all sedimentary rocks - ANS-65%
Sandstones make up how much of all sedimentary rocks - ANS-20 to 25%
Carbonate Rocks make up how much of all sedimentary rocks - ANS-10 to 15%
