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WORLD’S #1 ACADEMIC OUTLINE
Agate Calcite Galena Gypsum 2 Pyrite Quartz (Rose)
Biotite Mica Fluorite Gypsum 1 Muscovite Mica Quartz Sulfur (Native)
A PICTORIAL GUIDE TO MINERALOGY
METALLIC LUSTER
Mineral
Bornite Chalcopyrite Chromite Galena Goethite Graphite Hematite Limonite Magnetite Marcasite Native Copper Pyrite Sphalerite
Hardness Streak Color
3.0 3.5-4 5.5 2.5 5-5.5 1.0 5-6.5 5-5.5 6.0 6-6.5 2.5-3 6-6.5 3.5-4
black/gray dark gray brown gray brown/yellow dark gray reddish brown/yellow dark gray dark gray copper dark gray white/yellow
Specific Other Properties Gravity
5.1 4.2 4.7 7.5 4.3 2.2 4.9-5.2 4.2 5.2 4.9 8.9 5.0 4.0
red, purple, iridescent, brittle, soft yellow, brittle, conchoidal fracture silver, black, weakly magnetic silver, cubic cleavage brown to black black, greasy, writes silver, reddish, no cleavage brown, amorphous black, magnetic yellow/gold, brittle, no cleavage copper, brown, malleable fool’s gold, cubic crystals brown, dodecahedral cleavage, transparent
NON-METALLIC LUSTER
Mineral
Hardness Streak Color
Specific Luster Gravity
Other Properties
Agate (Quartz) 7
Apatite
5
Augite
5.5
Azurite
3.5-4
Barite
3
Biotite Mica
2.5-3
Calcite
3
Chalcedony (Quartz) 7
Chert (Quartz) 7
Chlorite
2
Chrysocolla
2-4
Corundum
9
Diamond
10
Dolomite
3.5-4
Epidote Flint (Quartz) Fluorite Garnet Glauconite Gypsum Halite Hematite Hornblende Jasper (Quartz) Kaolinite Limonite
6-7 7 4 7 2-2.5 2 2.5 1.5-5.5 5.5 7 1-2 1.5-5.5
Malachite
3.5-4
Muscovite Mica 2-2.5
Native Sulfur
1.5-2.5
Olivine
7
Opal
6
Plagioclase Feldspar 6
Potassium Feldspar 6
Quartz
7
Serpentine
2-5
Talc
1
Topaz
8
Tourmaline
7-7.5
Turquoise
5-6
1
white
2.5-2.8
white
3.1
white light blue white gray-brown white white white white light blue
3.3-3.5 3.7 4.5 2.7-3.1 2.7 2.5-2.8 2.5-2.8 2.6-3.0 2.0-2.4
white
4.0
white
3.52
white
2.8
white
3.4
white
2.5-2.8
white
3.0-3.3
white
3.4-4.3
green
2.4-2.9
white
2.3
white
2.1-2.6
red/brown 4.9-5.3
green
3.0-3.3
white
2.5-2.8
white
2.6
yellow/brown 3.6-4.0
green white
3.9-4.0 2.7-3.0
yellow white white white white white white
2.1 3.3 1.9-2.3 2.6-2.8 2.6 2.7 2.2-2.6
white
2.7
white
3.5
white
3.1
pale blue 2.7
vitreous varying banded colors,
no cleavage
vitreous brown, yellow, green,
conchoidal fracture
vitreous green, 2 cleavage@900
earthy blue, reacts w/HCl
vitreous crystals, 3 cleavage not@900
pearly
brown, one cleavage
vitreous colorless, rhombohedral cleavage
waxy
white, cryptocrystalline
waxy
gray, cryptocrystalline
vitreous green, one cleavage
vitreous blue, amorphous, conchoidal
fracture
adamantine brown, red, blue, purple, hard
adamantine colorless, hardest, conchoidal
fracture, octahedral cleavage
vitreous white, gray, pink, rhombohedral
cleavage
vitreous green-yellow, one cleavage
waxy
black, cryptocrystalline
vitreous violet, blue, octahedral cleavage
vitreous dark red, no cleavage
greasy green, marine origin
silky
colorless, white, one cleavage
vitreous colorless, cubic cleavage
earthy red, no cleavage
vitreous green, brown, cleavage@600-1200
waxy
red, cryptocrystalline
earthy white, gray, brown, one cleavage
vitreous yellow-brown, amorphous
to dull
silky
green, will react with HCl
pearly
colorless or silvery-white,
one cleavage
resinous yellow, conchoidal fracture
vitreous green-yellow, conchoidal fracture
greasy colorless, white, amorphous
vitreous black, white, gray, 2 cleavage@900
vitreous pink, white, 2 cleavage @ 900
vitreous many colors, conchoidal fracture
silky or green, gray, brown, fibrous
waxy
pearly or white, greenish-white, gray
greasy
vitreous yellow, brown, blue, green,
basal cleavage
vitreous yellow, green, brown,
no cleavage, conchoidal fracture
waxy
light blue green, microcystalline,
conchoidal fracture
MINERALS
A mineral is a naturally occurring, inorganic, solid material with a defined chemical composition and crystalline structure A. Atoms and Crystal Form:
1. Atom: The smallest particle of an element that maintains the element’s properties
2. Atoms are composed of neutrons, protons, and electrons
a. Atomic Structure: The arrangement of protons, neutrons and electrons
b. Atomic Number: Number of protons in a nucleus
c. Atomic Weight: Average weight of an atom d. Isotope: Forms of an element with identi-
cal atomic numbers, but different numbers of neutrons in the nucleus 3. Crystalline Structure: The specific and repeated arrangement of atoms 4. Crystal Form: The geometric shape of a crystal, determined by crystalline structure, can usually be observed at the surface of the mineral a. Crystal Face: Each flat surface of a mineral b. Cryptocrystalline: Crystals too small to see with the bare eye c. Amorphous: Noncrystalline, or lacking atomic structure due to rapid cooling, glassy appearance; example: opal d. There are 64 crystal forms separated into 6 classes: i. Isometric class: Equal measure ii. Tetragonal class: Square cross sections,
rectangular faces iii.Hexagonal/Triagonal class: Six-sided iv. Orthorhombic class: Rectangular profile,
rectangular faces v. Monoclinic class: Rectangular faces and
trapezoid faces vi. Triclinic class: Trapezoid faces
EXAMPLES OF CRYSTAL FORMS:
Cube (Isometric class): Galena
Octahedron (Isometric class): Magnetite
Hexagonal pyramid (Hexagonal class): Nepheline
Rhombohedron (Hexagonal class): Dolomite
Scalenohedron (Tetragonal class): Chalcopyrite
B. Mining 1. Ore: Useful metallic mineral found in large enough quantities to be profitable in mining 2. Variables in mining ores: a. Amount of metal present compared to total amount in Earth’s crust; small amounts may not be worth mining b. Cost to mine or accessibility to ore, i.e., an ore deep in the oceanic crust is more difficult and costly to mine than in the continental crust c. Value of the ore: Depends on the demand; a more precious metal may be mined in smaller quantities if in demand
C. Mineral Groups 1. Silicates: Minerals with silicon and oxygen
a. Silica tetrahedron: Silicon forms a pyra-
mid-shaped structure with oxygen, basic
building block for silicate minerals
b. Silicate structures and examples:
Isolated (single) olivine
Single Chain augite (pyroxene)
Double Chain hornblende (amphibole)
Sheet
biotite (mica)
3-D Framework feldspars, quartz
2. Non-Silicates
a. Carbonates: Minerals with carbon and
oxygen, including calcite, from which we
procure limestone (roads) and marble
(decorative slabs)
b. Oxides: Oxygen-based solids; example:
magnetite
c. Sulfides: Contain sulfur; example: pyrite
d. Sulfates: Contain sulfur and oxygen;
example: gypsum
e. Halides: Contain a halogen element and a
metal, halite
f. Native metals: Iron, zinc, gold, silver,
nickel, copper
D. Properties of Minerals
1. Luster: Appearance or quality of light reflect-
ed from the surface
a. Metallic: Resembles metal; example:
gold, silver, pyrite
b. Nonmetallic: Unlike metal
i. Adamantine: Resembles a diamond,
brightest luster
ii. Resinous: Resembles resin; example: sulfur
iii.Vitreous: Resembles glass, most common;
example: quartz and fluorite
iv. Pearly: Resembles Mother of Pearl; example:
muscovite, biotite (mica)
v. Silky: Mineral with fine fibers; example:
gypsum
vi. Waxy: Resembles wax; example: chalcedony
vii. Earthy: Resembles earthy materials like
dirt, having no reflection; example: baux-
ite, clay, diatomaceous earth 2. Color: The surface color of a mineral
a. Most minerals have a variety of colors;
example: quartz
b. Some minerals have a unique color that may
help identify it; example: sulfur is yellow
3. Hardness: The ability to withstand
scratching
a. Tested using an object or mineral of known
hardness on a mineral of unknown hard-
ness or vice versa
b. Moh’s hardness scale relates 10 common
minerals from hardest to softest
c. Scratch Test: Higher-numbered materials
can scratch lower-numbered materials
MOH’S SCALE
Hardness Mineral Object of known hardness
10
Diamond
9
Corundum
8
Topaz
7
Quartz
6
Feldspar
5.5
Glass, knife
5
Apatite
4
Fluorite
3.5
Penny (copper)
3
Calcite
2.5
Finger nail
2
Gypsum
1
Talc
2
4. Streak: Color of mineral in powdered form a. Created by scratching mineral on streak plate or unglazed porcelain (applies to minerals with a hardness of 6 or less; if greater than 6, the powdered form of the mineral is the streak color) b. Color of streak may differ from surface color; example: hematite is metallic silver while the streak is red-brown
5. Cleavage: Tendency to break or separate along a flat surface due to a lack of or weakness in atomic structure; example: muscovite, biotite (mica)
a. Cleavage plane: Flat surface created from cleavage breakage
b. Striation: Thin, straight cuts on the cleavage plane
c. Fracture: Surface created from breakage not related to atomic structure i. Uneven: Irregular, rough ii. Conchoidal: Curved, smooth surface; example: obsidian
NUMBER OF CLEAVAGE
Planes & Directions Drawing Example
1 (basal cleavage)
micas, chlorite
2 at 90˚
feldspar
2 not at 90˚
amphibole
3 at 90˚ (cubic cleavage)
galena
3 not at 90˚ (rhombohedral cleavage)
dolomite, calcite
4 (octahedral cleavage)
fluorite
6 (dodecahedral cleavage)
sphalerite
6. Specific Gravity a. The ratio of the weight of a mineral to the weight of an equal volume of water b. Density of water = 1gm/cm3=1gm/ml i.e., lead = 7.7, or is 7.7 times heavier than an equal volume of water c. Useful in comparing relative weights between minerals
7. Tenacity: Ability to withstand breakage a. Brittle: Will shatter when struck b. Malleable: Can be shaped c. Elastic: Returns to initial form d. Flexible: Pliable e. Splintery: Similar to wood
8. Special Properties a. Taste: Some minerals can be identified by taste; example: halite (salty) b. Smell: May help identify a mineral; example: kaolinite smells moldy when moist; sulfur has a unique smell c. Feel: Texture can be determined d. Reaction to Acid: Carbonate minerals will react to hydrochloric acid or vinegar e. Magnetic: Will be drawn to a magnet; example: magnetite
ROCK CYCLE
Magma
Crystallization
Igneous Rock
Melting Heat & pressure
Melting
Metamorphic Rock
Weathering, erosion
& deposition
Weathering, erosion
& deposition
Heat & pressure
Sediment
Sedimentary Rock
Cementation & compaction (lithification)
IGNEOUS ROCKS
A. Igneous Rocks: Molten rock from deep within the Earth that has cooled 1. Magma: Molten rock inside the Earth a. Produces intrusive igneous rocks b. Consists mainly of silicate materials c. Contains gases, such as water vapor d. Differs in rate of cooling, composition of chemicals, and amount of gases 2. Lava: Molten rock on the surface of the Earth a. Produces extrusive igneous rocks b. Most gaseous elements have escaped
IGNEOUS ROCK FORMATIONS
b. Pyroclasts: Lava projected from volcanic explosions that quickly cools
i. Ash, less than 2 mm in size
ii. Lapilli, between 2 and 64 mm in size
iii.Blocks, greater than 64 mm in size
C. Properties of Igneous Rocks
1. Texture: Determined by rate of cooling; faster cooling results in smaller crystals
a. Pegmatitic: Grains larger than 1 cm, very coarse, very slow-cooling;
example: diorite-pegmatite
b. Phaneritic: Grains between 1 and 10 cm, coarse; example: granite
c. Porphyritic: Large crystals embedded in small crystals; example:
basalt porphory
i. Phenocrysts: Large crystals, due to slow cooling
ii. Groundmass: Small crystals, due to rapid cooling
d. Aphanitic: Grains less than 1 mm, very fine, very fast-cooling; exam-
ple: rhyolite
e. Glassy: No crystals, amorphous; example: obsidian
f. Vesicular: Contains varying sizes of gas pockets that remain in the lava,
leaving the rock with voids; example: pumice
g. Frothy: Formed from gas pockets, porous texture; example: scoria
h. Pyroclastic: Made of pyroclasts; example: tuff
2. Mineral Composition: Determined by evaluating the percent present of
the following common minerals:
a. Plagioclase feldspar e. Quartz
b. Olivine
f. Amphibole
c. Potassium feldspar g. Biotite
d. Pyroxene
h. Muscovite
3. Color: Helps determine the mineral composition
a. Felsic: Light-colored, made of feldspars and silicates
i. Quartz
ii. Plagioclase feldspar
iii.Potassium feldspar
iv. Muscovite
b. Mafic: Dark-colored, made of magnesium and iron (ferric)
i. Olivine
ii. Pyroxene
iii.Amphibole
iv. Biotite
c. Ultramafic: Very dark-colored
d. Intermediate: Between light- and dark-colored
D. Bowen’s Reaction Series
If a mineral, which has already formed, remains in the magma, it will react with
the remaining magma to produce the next mineral in the sequence; for example,
olivine forms first; olivine then reacts with remaining magma to form pyroxene
BOWEN’S REACTION SERIES
Volcano Volcanic Ash
Volcanic Plug
Lava Flows
Stock
Laccolith Dikes
Sill
Batholith
B. Formations 1. Intrusive Igneous Rock: Formed inside the Earth’s crust in varying rock bodies a. Batholith: Largest intrusive igneous rock body, greater than 100 square miles, widens with depth (plutonic, very deep) b. Stock: Similar to but smaller than batholith, less than 100 square miles c. Laccolith: Bulge of magma parallel to bedding plane d. Sill: Thin sheet, runs parallel to bedding plane e. Dike: Cuts through formations, usually in fractures
2. Extrusive Igneous Rock: Formed on the surface of the Earth (volcanic) a. Lava flows: Lava seeping out of volcanoes
3
Magma Temperature
High (early crystallization)
Low (late crystallization)
Discontinuous Reaction Continuous Reaction
Series
Series
(Mafic Minerals)
(Felsic Minerals)
(Calcium-rich)
Olivine
Pyroxene
Plagioclase
Amphibole
Biotite
(Sodium-rich)
Potassium feldspar Muscovite Quartz
Rock Types
Peridotite Gabbro
or Basalt
Diorite or
Andesite
Granite or
Rhyolite
1. Continuous Reaction Series (Right side of the Bowen Series) a. Calcium-rich parts of the magma form small crystals of feldspar b. These react with sodium in the magma to become more and more sodium rich c. Crystal structure does not change
2. Discontinuous Reaction Series (Left side of the Bowen Series) a. Minerals that form react with remaining magma to form new mineral b. New mineral is the result of a structural change of previous mineral
3. End of Cooling a. When everything is almost cool, remaining magma will have high silicone content, and quartz will form b. When cooling is complete, minerals that cooled at the same time will usually be close to one another (feldspar, micas and quartz cool near one another to make granite)
IGNEOUS ROCKS
Basalt
Granite
Obsidian
Pumice
TABLE OF IGNEOUS ROCK
Color Index & Graphic Illustration
0
15
45
85
100
Felsic (Light) 100 Muscovite
Intermediate
80
Quartz
Mafic (Dark) Ultramafic
60
Mineralogical
Composition
as Percent of Volume
40
20
0
Potassium Feldspar (K-Spar)
Plagioclase
FeldsparFERROMAPGyrNoExSeIAnNe S
Biotite
Amphibole
Olivine
Red Granite
Red Scoria
Rhyolite
Volcanic Rock with Obsidian
Origin Texture
Pegmatic: Very
coarse-grained
GRANITEPEGMATITE
Intrusive
Phaneritic: Coarse-grained
GRANITE
Porphyritic RHYOLITE/ GRANITE
Aphanitic: Fine-grained
RHYOLITE
Rock Names DIORITE-
PEGMATITE
DIORITE
PORPHYRITIC/ ANDESITE/DIORITE
ANDESITE
GABBROPEGMATITE
GABBRO
PORPHYRITIC/ BASALT/GABBRO
BASALT
Extrusive
Glassy
OBSIDIAN
Frothy
PUMICE
SCORIA (VESICULAR
BASALT)
Pyroclastic or VOLCANIC TUFF (fragments < 2 mm)
fragmental
VOLCANIC BRECCIA (fragments > 2 mm)
PERIDOTITE
Rarely Encountered
SEDIMENTARY ROCKS
A. Sediments: Pieces or fragments from existing rock that
accumulate on the Earth’s surface
1. Weathering: Physical or chemical breakdown of rock that
creates sediments at or near the surface of the Earth
a. Mechanical weathering and erosion
i. Frost wedging
ii. Unloading
iii.Biological activity: Roots, burrows
b. Chemical weathering
i. Water to rust (oxidation)
ii. CO2 and water make carbonic acid iii.Granite reacts with water and gas to make clay minerals + potassium
and silica
2. Transport: Method of moving sediments
a. Running water, rivers c. Wind
e. Ground water
b. Glaciers
d. Gravity
f. Wave currents
3. Depositional environment: Places where the sediment is
deposited
a. Continental - deserts, lakes, river beds, swamps, caves
b. Continental and Marine - deltas, sand bars, lagunes, estuaries
c. Marine - the ocean floor
4. Lithification: Method of sediments becoming consolidated
sedimentary rocks
a. Compaction: Weight compresses deeper sediments
b. Cementation: Materials are “cemented” together from precipita-
tion of a mineral in spaces between sediment
c. Crystallization: Sedimentary rock created from a solution
B. Sedimentary rocks: Rocks formed from existing sediments
through lithification
1. Clastic rocks: (detrital)
a. Accumulated debris from weathering and transport
b. Made up of mostly clay minerals and quartz
c. Conglomerate: Made up of gravel-sized particles
2. Chemical rocks: Created from chemical precipitation
a. Formed from materials in solution in bodies of water
b. Most abundant form is limestone
3. Organic (Biochemical) rocks: Created from biological remnants,
such as plants, shells, bones, or other organic matter
C. Shapes, Sizes and Sorting of
Sediments
1. Shapes
a. Angular: Sediment has sharp corners and
edges
b. Rounded: Sediment has undergone abra-
sion and has rounded, smoothed edges
2. Sizes
a. Clay: <1⁄256mm, creates mudstone
b.
Silt:
Between
⁄1 256
and
⁄1 16
mm,
creates
silt-
Angular
stone
c.
Sand:
Between
⁄1 16
and
2
mm,
creates
sandstone
d. Pebble: Between 2 and 64 mm, creates a
conglomerate
e. Cobble: Between 64 and 256 mm, creates
a conglomerate
f. Boulder: >256 mm, creates a conglomerate
3. Sorting
a. Poorly-sorted: Particles of different sizes Well-Rounded
together, i.e., a glacier does not sort sedi-
ments
b. Well-sorted: Particles of the same size together, i.e., a river sorts
rocks from heaviest (upstream) to lightest (downstream)
4
(Sedimentary Rocks continued)
D. Properties of Sedimentary Rocks
1. Texture a. Clastic: Made of transported sediments and deposition; observe particle size, shape of grain and how well-sorted b. Bioclastic: Remains of organic material c. Crystalline: Interlocking crystals of different sizes, considered dense if crystals are less than 1⁄4 mm d. Amorphous: Dense, having no crystal structure e. Oolitic: Made of oolites, small round particles made of calcium carbonate
2. Composition: Possible matter found in sedimentary rocks
a. Carbonate, test with HCl; examples: calcite and dolomite
b. Silica; examples: quartz and chert
c. Clay minerals; examples: kaolinite, silicate
d. Organic matter; examples: plants, shells, bones
e. Evaporites, minerals created from a solution; example: gypsum
f. Rock Particles; example: conglomerates
g. Heavy Minerals; example: garnet h. Feldspar, known as arkosic E. Sedimentary Structures:
Structural features resulting from sediment transportation and deposition 1. Stratification: Distinct layers (strata or bed) formed from moving and depositing sediments 2. Cross Bedding: Stratification at an angle 3. Graded Bedding: Each bed is comprised of sediments that increase in size as the depth of the bed increases (coarsest on bottom); common for deep marine environments 4. Surface Impressions: Impressions preserved in the bed a. Ripple Marks: Marks preserved
from flow in one direction (asymmetrical) b. Oscillation Marks: Marks preserved from flow back and forth (symmetrical) c. Mud Cracks (Desiccation marks): Markspreservedfromexposure to air d. Raindrop Impressions: Marks preserved from rain e. Trace Fossils: Marks preserved from the movement of animals
Poorly-Sorted Well-Sorted
Sedimentary Rock: Durango, CO Chert Coquina Dolomite
Shale
Sandstone
Limestone
Depth in kilometers Pressure in Kb
CLASTIC SEDIMENTARY ROCKS
Name
Arkose Breccia Calcarenite Claystone Conglomerate Graywacke Lithic Quartz Shale Siltstone
Texture (of sediments)
coarse sand, angular pebble-sized, angular sand size clay size pebble-sized, round sand and clay size sandstone sand size sandstone sand size, rounded clay and silt size silt size
General Description
feldspar and quartz present in matrix of cemented sand calcite present minerals not visible, smooth in matrix of cemented sand quartz/sand mixed with clay rock fragments quartz present claystone or siltstone that has layers minerals not visible, earthy
CHEMICAL SEDIMENTARY ROCKS
Name
Chemical Limestone Chert Dolomite Ironstone Rock Gypsum Rock Salt Travertine
Texture (of sediments)
visible crystals dense crystalline, dense dense visible crystals visible crystals dense
General Description
has calcite, will react w/HCl conchoidal fracture powder will react w/HCl iron present, dark-colored gypsum present halite present, salty will react w/HCl, dark bands
ORGANIC (BIOCHEMICAL) SEDIMENTARY ROCKS
Name
Bituminous Chalk Coquina Diatomite Peat Skeletal Limestone
Texture (of sediments)
coal bioclastic, dense bioclastic bioclastic bioclastic bioclastic bioclastic
General Description
black, like soot white, will react w/HCl cemented shells like chalk, no HCl reaction plant material shells, will react w/HCl
METAMORPHIC ROCKS
A. Metamorphism: To change form within the Earth from existing
rocks through heat, pressure and chemical activity, not a result of
weathering or sedimentation
1. Heat
a. Most important agent
b. Provides energy for chemical reactions
c. Created from igneous rock bodies movement through the existing rock
d. Created from geothermal gradient, 25˚C increase in temperature with
each kilometer increase in depth (geothermal gradient)
e. For example, clay recrystallizes into feldspar and mica at high temperatures
2. Pressure and Stresses a. Confining pressure GEOTHERMAL GRADIENT
i. Equal pressure on all
Temperature oC
sides due to deep burial
00
200 400 600 800 0
ii. Depth determines
amount of pressure
5
iii.For example, an
2
object in the water
10
has equal amounts of
pressure on all sides
15
4
b. Directed Stress:
Specific pressure to
20
a rock, not uniform,
6
such as in the form-
25
ing of a mountain
i. Differential stress:
30
8
Stresses in different
directions, not equal
35
10
ii. C o m p r e s s i v e
stress: Stress that causes the object to be squeezed
iii.Shear stress: Stresses in opposite directions that cause the object to move
parallel to the stress
3. Chemical Activity
a. Change in atomic composition due to heat and/or pressure may cause
crystal to recrystallize
b. Water is the most common chemical agent
5
Metamorphic Rocks continued
B. Types of Metamorphism 1. Contact metamorphism: Changes caused by proximity to magma or deep, hot rock 2. Regional metamorphism: Changes caused by intense stress and high temperatures 3. Hydrothermal metamorphism: Changes caused by hot liquids 4. Fault Zone metamorphism: Changes caused by fault movement
C. Degrees of Metamorphism 1. Metamorphic grade: Degree of metamorphism applied to rock a. High-grade: Very high amounts of heat and pressure; example: gneiss b. Intermediate-grade: Medium amounts of heat and pressure; example: schist c. Low-grade: Lower amounts of heat and pressure, more dense and compact; example: slate 2. Metamorphic facies: Minerals present in metamorphic rock correlate to amount of heat and pressure a. Low pressure, high temperature; hornfels facies b. High pressure, high temperature; granulite facies, amphibolite facies, and greenschist facies c. High pressure, low temperature; blueschist facies and eclogite facies
D. Changes in Mineralogy: Changes in texture or composition of the mineral due to heat and pressure
1. Recrystallization: Changed by smaller crystals joining to create larger crystals of the same mineral; common
2. Neomorphism: New minerals created from existing mineralogical compositions
3. Metamorphism: New minerals created through gaining or losing chemicals
E. Properties of Metamorphic Rocks 1. Texture a. Foliated texture: Contains foliations, minerals brought into line or with one another; layers, due to heat and pressure, common for regional metamorphism; type of foliation can identify rock
i. Slaty: Caused by low-grade metamorphism; dense rock containing very fine-grained mica minerals, separates in sheets, texture of slate
ii. Phyllitic: Caused by low-grade to intermediate-grade metamorphism; rock containing very fine-grained mica and chlorite minerals that form in a wave-like manner; glossy luster; looks wrinkled; texture of phyllite
iii.Schistose: Caused by intermediategrade metamorphism; medium- to coarse-grained platy minerals such as micas, chlorite, and quartz present, texture of schist
iv. Gneissic: Caused by intermediategrade to high-grade metamorphism; rock containing layers of varying medi- Black Canyon of Gunnison um to coarse minerals, light and dark layers alternating, texture of gneiss
v. Migmatitic: Caused by extreme heat and pressure, melting; rock containing igneous (granite) and metamorphic rock, texture of migmatite
b. Nonfoliated texture: Lacks foliations, or layers, of minerals; granular, common for contact metamorphism i. Cataclastic: Made of fragments or angular pieces of existing rocks created by grinding, often near faults, hydrothermal veins ii. Granular: Rocks containing minerals of similar size crystals that can be seen with the bare eye, such as quartzite iii.Microgranular: Rock containing minerals of similar size that cannot be seen with the bare eye, such as hornfels iv. Glassy: No crystals can be seen, smooth, has conchoidal fracture; example: anthracite coal v. Porphyroblastic: Rock containing large crystals (porphyroblasts) in a matrix of finer crystals, schist
2. Composition: Assists in identification of nonfoliated rocks; some properties of the metamorphosed rock (sedimentary, igneous or metamorphic) can remain in the new rock
a. Sandstone: Can create quartzite
b. Limestone: Can create marble
c. Basalt: Can create schist or amphibolite
d. Shale: Can create slate
e. Granite: Can create schist
f. Rhyolite: Can create schist
Anthracite coal
Gneiss
Marble
Schist
Slate
TABLE OF METAMORPHIC ROCKS
Name
Texture
Anthracite Coal Gneiss
nonfoliated, glassy foliated, gneissic
Type of Metamorphism
regional metamorphism regional metamorphism
Greenstone Hornfels Marble Migmatite Phyllite Quartzite Schist Serpentine Skarn Slate
nonfoliated, granular nonfoliated, microgranular nonfoliated, granular foliated, migmatitic foliated, phyllitic nonfoliated, granular foliated, schistose nonfoliated, granular nonfoliated, granular foliated, slaty
regional metamorphism contact metamorphism contact metamorphism regional metamorphism regional metamorphism contact metamorphism regional metamorphism regional metamorphism contact metamorphism regional metamorphism
Preexisting Rock
bituminous coal schist
gabbro or basalt many rocks limestone or dolomite gneiss and granite slate quartz sandstone phyllite basalt or gabbro limestone or dolomite shale or mudstone
Description
shiny, black, conchoidal fracture coarse grains, undergoes neomorphism, contains layers of light and dark bands, quartz and micas present undergoes metasomatism conchoidal fracture, dense, dark gray to black recrystallized, white, gray, pink alternating metamorphic and igneous rock wrinkly, contains micas, crystals not visible, shiny hard, recrystallized, white, brownish wrinkly, porphyroblasts, crystals visible undergoes metasomatism undergoes metasomatism breaks along flat surface, black to dark gray, dense
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ISBN-13: 978-142320700-9 ISBN-10: 142320700-9
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DISCLAIMER
This QuickStudy® guide is a basic outline of common rocks and minerals. Due to its condensed nature, we recommend you use it as a guide but not as an indepth reference.
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