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68 Cards in this Set
- Front
- Back
Criteria to be a mineral |
-Naturally occurring -Inorganic -Solid -Known and fixed chemical composition -Known and fixed crystalline structure |
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Color |
-A mineral property -How a mineral appears in light -Caution: Some minerals naturally come in a variety of colors & processes alter the original color |
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Streak |
-A mineral property -Scratching a mineral on a streak plate -Useful for relatively soft minerals only |
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Luster |
-A mineral property -How a mineral reflects light -Metallic vs. Non-metallic |
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Hardness |
-Resistence to abraison -Mohs scale of hardness 1. Talc 2. Gypsum 3. Calcite 4. Flourite 5. Apatite 6. Orthoclase feldspar 7. Quartz 8. Topaz 9. Corundum 10. Diamond |
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Crystal form |
-A mineral property -Preferred growth shape of particular minerals |
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Fracture and cleavage |
-A mineral property -How minerals break under applied stress |
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Fracture |
-Mineral breaks along irregular or curved surfaces -Conchoidal fracture: Breakage along curved surfaces -Non-conchoidal fracture: breakage along irregular surfaces |
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Cleavage |
-Mineral breaks along smooth, parallel planes -1 direction (basal cleavage) -2 directions (prismatic cleavage) -3 directions at 90° from each other (cubic cleavage) -3 directions not at 90° from each other (rhombohedral cleavage) -4 directions (octahedral cleavage) |
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Other properties associated with minerals |
-Specific gravity -Odor -Taste -Reaction to acid -Magnetism |
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Silicate minerals |
-Form from cooling and crystallization of molten rock -Contain silicon (Si) bonded to oxygen (O) -Quartz is the simplest one -Some contain silicon-oxygen tetrahedrons |
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Silicon-oxygen tetrahedron |
-Fundamental building block of silicate minerals (besides quartz) -1 Si ion surrounded by 4 O ions to form a 3 sided pyramid |
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Non-silicate minerals |
-Don't contain silicon -Numerous classes -Native elements: composed of single element found in nature -Sulfides: contain sulfide (S) -Oxides: contain oxide (O) ion -Carbinates: contain carbonate (CO3) ion |
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Rocks |
-Aggregations of minerals -May be composed of multiple minerals or multiple crystals of a single mineral -Three types: igneous, sedimentary, and metamorphic |
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Igneous rocks |
-Formed through cooling, and solidification of molten rock -May also form through accumulation of material produced by volcanic activity -Two types: intrusive and extrusive |
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Intrusive |
-Magma solidifies and/or interacts with Earth materials relative deep underground -Slower cooling = larger crystals |
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Extrusive |
-Magma solidifies and/or interacts with other Earth materials at or near the surface -Faster cooling = smaller crystals |
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Igneous rock textures |
-Phaneritic: coarse-grained texture, associated with intrusive rocks, big crystals -Aphanitic: fine-grained texture, small crystals, associated with extrusive rocks |
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Igneous rock compositions |
-Definied by the amount of silica present -Mafic magma: low silicon, dark in quartz, lacking quartz -Felsic magma: high silicon, light in color, abundant quartz -Intermediate magma |
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Phaneritic, mafic rock |
Gabbro Large crystals, intrusive, dark in color |
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Phaneritic, felsic rock |
Granite Large crystals, light in color, intrusive |
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Aphanitic, mafic rock |
Basalt Small crystals, extrusive, dark in color |
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Aphanitic, felsic rock |
Rhyolite Small crystals, extrusive, light in color |
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Sedimentary rocks |
-Formed through cementation of loose, pre-existing solid particles (sediment) -Four primary types: Volcanogenic, organic, chemical, clastic |
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Volcanogenic sedimentary rocks |
-Produced by volcanic activity -Can be considered an overlap with igneous rocks -Tuff, pumice, and bentonite |
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Organic sedimentary rocks |
-Composed of carbon-based particles produced directly by biological processes -Accumulations of non-mineralized biological matter -Coal: produced by consolidation of plant matter |
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Chemical sedimentary rocks |
-Produced by low temperature and pressure chemical reactions -Two types: carbonate and evaporite |
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Carbonate rocks |
-Tyos of chemical sedimentary rock -Composed of carbonate-based particles -Will react with acid -Ex. Limestone |
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Evaporite rocks |
-Type of chemical sedimentary rock -Composed of salts produced by evaporation -Ex. Rock salt: composed of halite -Ex. Rock gypsum: composed of gypsum |
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Clastic sedimentary rocks |
-Produced by breakdown of pre-existing rocks into loose particles -"Typical" sedimentary rocks |
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Making a clastic rock |
1. Weathering 2. Erosion 3. Deposition 4. Lithification |
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Weathering |
-Responsible for production of clastic sediments -Processes that change the physical or chemical character of rocks at or near the surface -Breakdown of pre-existing rocks into smaller pieces without transporting those pieces -Two types: mechanical & chemical |
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Mechanical weathering |
-Physical disintegration of rock into smaller pieces -Does not affect composition of pre-existing rock -Ex. Granite mountain broken up into granite blocks.. they are still granite -Exposes rocks to more weathering by increasing surface area |
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Mechanical weathering |
-Physical disintegration of rock into smaller pieces -Does not affect composition of pre-existing rock -Ex. Granite mountain broken up into granite blocks.. they are still granite -Exposes rocks to more weathering by increasing surface area |
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Frost wedging |
-Water seeps into a crack in a rock, then freezes, resulting in expansion and fracturing of rock |
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Root wedging |
-Plant roots force their way into rocks and split them apart |
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Pressure release |
-Intrusive igneous bodies expand and crack when exposed to the low pressure of the surface |
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Thermal expansion |
-Exteriors of rocks are heated more than interiors, so differential expansion occurs and produces fractures |
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Chemical weathering |
-Breakdown of rocks via chemical interactions -Changes composition of pre-existing material; new products are formed |
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Oxidation |
-Iron in rocks reacts with oxygen in water or atmosphere to produce iron-oxides -"Rusting" of rocks -Produces new minerals; weakens origin rock |
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Dissolution |
-Acids dissolve away some minerals -Fizzing of carbonate rocks |
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Partial solution |
-Chemically complex minerals are altered to a residue of clays |
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Erosion |
-Transportation of particles away from site of weathering and to site of accumulation -High weather = low erosion -Agents of erosion: water and wind, gravity, biological activity, glaciers |
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Deposition |
-Sediments are transported to a place where they can accumulate and become buried (depositional environment) |
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Lithification |
-Conversion of unconsolidated sediments into hard, sedimentary rock -Two steps: First, buried sediments are compacted Second, spaces between grains are filled with chemically precipitated cement |
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Gravel |
-Coarsest clastic sediment (larger than 2mm) -Conglomerate: rock made of gravel-sized sediment with rounded edges -Breccia: rock made of gravel-sized sediment with angular edges |
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Sand |
-Intermediate clastic sediment (1/16 to 2mm) -Sandstone: over generalized term for rock made of sand-sized sediment |
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Mud |
-Fine clastic sediment (smaller than 1/16mm) -Silt: 1/256-1/16mm -Clay: smaller than 1/256mm |
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Mudrocks |
-General term for rocks made of mud-sized sediment -Three kinds: siltstone, shale, and mudstone |
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Siltstone |
-Type of mudrock -At least 2/3 silt -Fine-grained, but gritty; faintly visible grains |
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Shale |
-Type of mudrock -Clay-dominated and laminated -No visible grains, smooth to the touch |
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Mudstone |
-Type of mudrock -Clay-dominated and not laminated -No visible grains; smooth to the touch |
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Metamorphic rocks |
-Form through alteration of pre-existing rocks at high pressures and temperatures, but without melting them |
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Metamorphism |
-Changes to rock texture and mineral composition occur -Textural changes affect the size, shape, and arrangement of mineral crystals -Compisitional changes affect the specific minerals present in a metamorphic rock |
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Protolith |
-The parent rock -Changes occur to the protolith to result in metamorphic rocks |
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Primary controls of metamorphism |
-Composition of protolith -Presence of fluids -Temperature -Pressure |
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Composition of protolith |
-Control of metamorphism -Elements in the parent rock are the "raw ingredients" for minerals in the metamorphic rock |
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Presence of fluids |
-Control of metamorphism -Fluids help facilitate chemical interactions and move ions around |
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Temperature |
-Control of metamorphism -Certain reactions and changes occur once a specific temperature is reached |
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Pressure |
-Control of metamorphism -Minerals precipitated under high pressure are smaller and denser than low pressure minerals in the parents rock |
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Differential stress |
-Pressure applied to rocks more strongly in one direction than others |
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Foliation |
-Layered (planar) texture in metamorphic rocks formed by alignment of platy or needle-shaped minerals that crystallized within a rock subjected to differential stress -Shows direction of differential stress |
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Marble |
-Non-foliated metamorphic rock -Coarse-grained rock composed of interlocking crystals of calcite -Metamorphosed limestone -Will react with acid |
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Quartzite |
-Non-foliated metamorphic rock -Quartz grains welded together to produce a fine-grained, physically strong rock -Metamorphosed quartz sandstone |
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Slate |
-Foliated metamorphic rock -Lowest metamorphism -Very fine-grained rock that splits into thin, flat, parallel layers -Earth, non shiny surfaces -Only from mudrock protoliths |
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Phyllite |
-After slate, still low metamorphism -Fine-grained rock that has shiny surfaces (a "sheen") due to microscopic mica formation -Essentially only from mudrock protoliths |
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Schist |
-After phyllite, much more metamorphism -Coarse-grained rock with noticeably aligned platy and elongate minerals -Relatively strong metamorphism -Multiple protoliths can produce schists -Variable in composition |
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Gneiss |
-After schist, most extreme metamorphism -Coarse-grained rock with distinct light and dark banding resulting from segregation of minerals in to separate layers -Multiple protoliths can produce gneisses |