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64 Cards in this Set
- Front
- Back
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his is a luster with a shiny, glass-like appearance..
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Vitreous
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Mineral Lusters
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Metallic
Submetallic Non Metallic |
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The tendency of a mineral to break along preferred planes
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Cleavage
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Smoothly curving, clamshell-shaped surfaces along which materials with no cleavage planes tend to break.
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Conchoidal fracture
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A singl, continuous piece of a mineral bounded by flat surfaces that formed naturally as the mineral grew.
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Crystal
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The resistance of a mineral to scratching; a harder mineral can scratch a softer mineral.
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Hardness
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The way a mineral surface scatters light.
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Luster
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A homogenous, naturally occurring, solid inorganic substance with a definable chemical composition and an internal structure characterized by an orderly arrangement of atoms, ions, or molecdules in a lattice. Most are inorganic.
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Minerals
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a list of ten minerals in a sequence of relative hardness, with which other minerals can be compared
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Mohs hardness scale
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The color of the powder produced by pulverizing a mineral on an unglazed ceramic plate.
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Streak
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The chemical composition and crystalline structure of each mineral determines a set of physical properties that include ...
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harness, luster, streak, and cleavage/fracture
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Softest mineral
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Talc. Hardness = 1
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Harness:
Natural fingernail Copper penny Window glass Masonary nail Streak plate |
Harness:
Natural fingernail 2.5 Copper penny 3.5 Window glass 5.5 Masonary nail 5.5 Streak plate 6.5 |
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Luster types (5)
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Metallic - opaque and reflects light very well, shines in a way reminiscent of polished metal; pyrite is an example
Submetallic - opaque and reflects light poorly like dull, unpolished metal; examples include sphalerite and graphite. Earthy - dull, reflects little light, reminiscent of dirt Vitreous - glassy, like glazed porcelain or window glass; examples include quartz, feldspar. Pearly - Iredescent in a way similar to that seen in natural pearls or the inside of shells; examples include muscovite and gypsum. |
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Hardness of 6.5 is tested on
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Streak plate
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Cleavage angles are ...
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0/180 - Biotite
90 Rhombic - Right angles 60/120 Cubic (Legos) - Halite |
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Rough breaks in minerals
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Fracture. Opposite of Cleavage
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Special properties of minerals
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Magnetism - magnetite
Feel - talc is slippery, halite may feel greasy Reaction to acid - carbonate Taste - Halite |
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Mineral ID Steps
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Luster
Fracture or cleavage Hardness |
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Mineral -Hardness
Talc Feldspar Calcite Hornblende Quartz |
Mineral/Hardness
Talc - 1 Feldspar - 6 Calcite - 3 Hornblende - 5-6 Quartz - 7 |
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Mineral - Luster
Gelena Talc Quartz Hermatite Gypsum |
Mineral - Luster
Gelena - Metallic Talc - Pearly/Greasy Quartz - Glassy Hermatite - Earthy Gypsum - Glassy |
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Mineral - Streak
Galena Hematite Plagioclase Hematite Hornblend |
Mineral - Streak
Galena - Gray Hematite - Brown Plagioclase - Colorless Hematite - Green/Gray Hornblend |
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Mineral - Cleavage
Biotite Orthoclase Feldspar Calcite Halite Quartz |
Mineral - Cleavage
Biotite - Y, 1, 180 Orthoclase Feldspar - Y, 2, 90 Calcite - Y, 3, 60/120 Halite - Y, 3, 90 Quartz - None |
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Galena - 2.5-2.8
Graphite - 1-2 |
Metallic to Submetallic Luster and Exhibit Cleavage
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Pyrite - 6-6.5
Hematite - 5-6.5 Magnetite - 6 |
Metallic to Submetallic Luster and Exhibit Fracture
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K-Spar - 6-7
Plagioclase - 6-6.5 Hornblende - 5-6 Dolomite - 3.5-4 |
Nonmetallic Luster, Cleavage, and have Mohs Harness of 4 to 7
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Fluorite - 4
Calcite - 3 Biotite - 2.5-3 Chlorite - 2-2.5 Muscovite - 2-2.5 Halite - 2-2.5 Gypsum - 1.5-2 Talc - 1 |
Nonmetallic Luster, Cleavage, and Mohs Harness of 1 to 4
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Corundum - 9
Tourmaline - 7-7.5 Garnet - 6.5-7.5 Quartz - 7 Olivine - 6.5-7 Hematite - 5-6.5 Bauxite - 1-3 |
Nonmetallic Luster and Exhibit Fracture
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Very fine grain size
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< 1/256 mm. characteristic of shale and mudstones. Individual particles are invisible to the eye, and the rock surface feels very smooth. This is hte most common type of detrital sedimentary rock.
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Fine grain size
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1/256 to 1/16 mm. Grains are characteristic of siltstone. Individual particles are invisible to the eye, and the rock surface may feel slightly gritty, particularly if you run your fingernail or tooth across the surface.
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Medium grain size
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1/16 to 2 mm. Characteristic of sandstone and arkose (a specific subset of sandstone). Individual particles are visible.
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Coarse grain size
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larger than 2 mm. Found in conglomerate and breccia can be car sized or larger, but more comonly are the size of peas to apples.
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Sedimentary Sorting:
Well sorted Moderately sorted Poorly sorted Bimodal sorting |
Sorting:
Well sorted - all of the grains are very similar in size. Moderately sorted - grain size varies, but not over a broad range. Poorly sorted - a wide variety of grain sizes if present. Bimodal sorting - two grain sizes are present, often coarse and very fine. |
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Sedimentary Shapes
Angular Sub-angular Sub-rounded Rounded |
Sedimentary Shapes
Angular - grains appear freshly broken with sharp edges and corners. Sub-angular - corners and edges and edges of the grains are slightly rounded off. Sub-rounded - the grains lack sharp corners or edges. Rounded - grains are roughly spherical with few, if any flat surfaces. |
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Most common observed sedimentary structure, and consists of parallel, planar features within the rock. Each individual application of sediment settles downwards to create a thin layer that covers a large area. Subsequent beds may have different grain sizes or mineral composition, creating a series of parallel layers.
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Bedding
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Feature limited to the mud rocks. Both are composed of very fine particles, however shale will tend to break along roughly parallel surfaces, while mudstone does not. Shale is said to exhibit, while mudstone is massive.
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Fissility
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Waves and currents create small undulations in the bottom sediments that can be preserved when the sediments are lithified. The shape of the ripples can tell us if the rocs were formed on a beach or in a stream, and what direction the water was flowing.
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Ripple marks
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Occur if a mass of poorly sorted sediment is suddenly dumped into still water. In this circumstance, the larger particles will settle to the bottom first, and the smallest ones last. Particles become finer as you go from the base to the top.
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Graded Beds
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Cohesive mud is deposited, dries out, shrinks, and pulls apart to form cracks. Once mud cracks form they often get filled up with coarser grained sands. In rocks, the sand filled portion is often preserved whereas the mud breaks apart and disintegrates. The presence of mud cracks tells us that the mud was exposed to the air after the mud was deposited.
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Mud cracks
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Experiences an in situ change to the mineralogic composition and texture without melting
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Metamorphic rock
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Recrystalization that is driven by some combination of elevated temperature, pressure, and shear
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Metamorphic rock
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Foliated and non-foliated
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Metamorphic rock
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Process are changes to the mineralogy, texture, or internal structure of a rock that is more extreme than those resulting from the simple diagenetic processes (compaction, cementation) that produce sedimentary rocks.
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metamorphism
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individual mineral crystals within the rock have transformed into new crystals while remaining solid.
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metamorphic recrystalization
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depend on both the conditions that lead to metamorphism, principally pressure and temperature, and the minerals that are present in the parent/protolith rock.
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metamorphic results of recrystalization
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new crystals form during recrystalization are flat, or elongated, then they will grow so that their long sides are perpendicular to the direction of maximum pressure. Forms parallel mineral crystals.
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foliated metamorphic rocks
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Increased pressure and/or temperature during recrystalization.
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metamorphic grade: low, intermediate, high
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rocks that exhibit a textrue that lacks any preferential fabric. Minerals crystals that form during this process are not elongated; for example, calcite as opposed to mica. Minerals that change size and/or shape (e.g., calcite, quartz) during metamorphosis rather than becoming a new mineral tend to form these rocks. Thus, although this is a textural term, its occurrence is highly dependent on the composition of the protolith.
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non-foliated metamorphic rocks
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a sliding motion in which part of a rock moves in one direction while the rest of it moves in the opposite direction, altering the shape of grains in the rock, and can also change their size.
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shear deformation
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Identifying metamorphic steps
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1. igneous, sedimentary, or metamorphic
2. foliated or non-foliated 3A foliated - focus on the degree of the foliation, size of the individual crystals, and any segregation into alternating bands of light and dark minerals. 3B non-foliated - mineral composition is the key to id. |
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What property is used to classify non-foliated metamorphic rocks
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orientation of crystal grains
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mica
flackey black yes foliated CC Cookies - amphibolite banding - gneiss acid green scratch sheen/plates - phylyte |
classifying metamorphic rock notes
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Mica/Feldspar
Quartzite Muscovite Calcite Mica Hornblende Mica/hornblende mica |
Mica/Feldspar - foliated, nodules, shiney, banding
Quartzite - scratches glass Muscovite - flakes Calcite - acid Mica - dull, not visable grains Hornblende - foliated plated shiney/black Mica/hornblende - shiney layers mica |
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Protoliths --
Amphibolite Stretched Pebble Slate Greenstone Schist Marble Gneiss Schist Phyllite Quartsite |
Protoliths --
Amphibolite - Basalt Stretched Pebble - conglomerate Slate - shale (foliated) Greenstone - gabbro Schist - granite Marble - limestone Gneiss - shale, granite, rhyolite Schist - shale (foliated) Phyllite - slate (foliated) Quartsite - sandstone |
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TEXTURE --
Amphibolite Stretched Pebble Slate Greenstone Schist Marble Gneiss Schist Phyllite Quartsite |
TEXTURE --
Amphibolite - Non-foliated Stretched Pebble - Non foliated Slate - Foliated Greenstone - Non-foliated Schist - Foliated Marble - Non-foliated Gneiss - fliated Phyllite - foliated Quartsite - non-foliated |
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METAMORPHIC GRADE OR CRYSTAL SIZE
Amphibolite Stretched Pebble Slate Greenstone Schist Marble Gneiss Schist Phyllite Quartsite |
METAMORPHIC GRADE OR CRYSTAL SIZE
Amphibolite - large Stretched Pebble - Choc Chip Cookie Slate - - Low Greenstone - small Schist - Intermediate Marble - small Gneiss - gneiss Schist - intermediate Phyllite - low Quartsite - small |
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METAMORPHIC GRADES
Slate Phyllite Schist Gneiss Migmatite |
METAMORPHIC GRADES
Slate - Low Phyllite - Low Schist - Intermediate Gneiss - High Migmatite - High |
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Common Detrital Rocks --- 2nd test meta
Shale Siltstone Sandstone Arkose Conglomerate Breccia |
Common Detrital Rocks --- 2nd test meta
Shale - very fine <1/256 mm Siltstone - fine 1/16 to 1/256 mm Sandstone - mediaum 1/16 to 2 mm Arkose - medium 1/16 to 2 mm Conglomerate - coarse >2mm Breccia - coars > 2 mm |
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composed of clay-sized particles (not visible) typically black, brown, or red in color. rock may split along parallel surfaces (fissility). feels smooth when dragged across a fingernail or tooth softer and less dense than basalt, softer than slate. 2nd test meta
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Shale - very fine
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composed of silt-sized particles (not visible) typically black, brown, or red in color massive, does not display fissility often feels gritty when dragged across a fingernail or tooth. 2nd test meta
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Siltstone - fine
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individual grains are visible. mostly made of quartz. strongest forms have silica-cement. weak forms have hematite cement and may fall apart. 2nd test meta
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Sandstone - medium
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contains large amounts of feldspar may be pinkish/reddish in color often poorly sorted. 2nd test meta
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Arkose - medium
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rounded grains larger than 2mm in diameter may have a matrix of finer grains. 2nd test meta
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Conglomerate and Bredcia - coarse
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ROCK NAME - MAJOR COMPONENT -- FIRST TEST META
Chert - quartz Limestone - calcite Coal - altered plant matter Rock Gypsum - gypsum Rock Salt - halite |
ROCK NAME - MAJOR COMPONENT FIRST TEST META
Chert - quartz --- microcrystaline quartz. conchoidal fracture. occurs in many colors. Limestone - calcite --- all forms react with HCL. formed from micro shell frags. coquina is made of visible shell frags. Coal - altered plant matter ---- has a lower density than most rocks. no visible organic matter. Rock Gypsum - gypsum ---- soft white evaporite rock. fibrous look. may be mixed with clastic sediments (i.e., dirty) Rock Salt - halite ----- chemically precipitated evaporite rock. often translucent color. tastes like salt. |
