Wards1-100
Wards1-100(contued)
Wards101-130 Wards131-160
Wards131-160(continued)
Wards161-190 Wards191-200
Wards Rock Collection
1-100
Wards1-100
Wards1-100(contued)
Wards101-130 Wards131-160
Wards131-160(continued)
Wards161-190 Wards191-200
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Phonolite Porphyry Location: N/A Description: are fine-grained, undersaturated, intermediate igneous rocks, with or without phenocrysts, consisting primarily of alkali feldspars and feldspathoids together with pyroxenes and amphiboles, usually sodic varieties.
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Nepheline Syenite Location: Wausau, Marathon co., WI Description: Nepheline syenite is a medium to coarse-grained, light- to medium-gray, igneous rock that is composed predominantly of orthoclase and has a granite-like appearance. It may be distinguished from granite by little or no quartz. In Arkansas, nepheline syenite has been intruded into the sequence of Paleozoic sedimentary rocks. Locally, quarrymen recognize "blue granite" and "gray granite" varieties. |
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Nepheline Syenite Location: Little Rock, Arkansas Description: Nepheline syenite is a medium to coarse-grained, light- to medium-gray, igneous rock that is composed predominantly of orthoclase and has a granite-like appearance. It may be distinguished from granite by little or no quartz. In Arkansas, nepheline syenite has been intruded into the sequence of Paleozoic sedimentary rocks. Locally, quarrymen recognize "blue granite" and "gray granite" varieties.
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Quartz Syenite Location: Egeria, CO Description: A quartz-bearing plutonic rock, or rock group, intermediate in composition between true syenite and granite; 5-20% of the light-colored minerals are quartz. |
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Alkali Granite Location: Quincy, MA Description: Interlocking
mosaic of microperthitic K-feldspar,zoned plagioclase, clinopyroxene |
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Quartz Felsite Porphyry Location: Marblehead, MA Description: Keratophyres are Na-rich
extrusive rocks, containing pure sodic plagioclase with or without quartz. |
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Hornblende Granite Location: Rockport, MA Description: Granites are phaneritic, alkili-rich, silica-oversaturated rocks consisting of one or two feldspars, quartz, and a variety of mafic and opaque phases. In this instance the dominate mineral is hornblend.. |
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Porphyritic Biotite Granite Location: St. MN Decription: Granites are phaneritic, alkili-rich, silica-oversaturated rocks consisting of one or two feldspars, quartz, and a variety of mafic and opaque phases. In this instance the dominate mineral biotite. |
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Porphyritic Syenite Location: Wausaw, WI Description: are holocrystalline course- to medium-grained intermediate igneous rocks in which the dominate mineral is alkali feldspar. |
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Muscovite-Biotite Granite Location: Concord, NH Description: Granites are phaneritic, alkili-rich, silica-oversaturated rocks consisting of one or two feldspars, quartz, and a variety of mafic and opaque phases. In this instance the dominate minerals are the muscovite and biotite. |
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Obsidian Location: Lake County, OR Description: Obsidian is dense volcanic glass, usually rhyolite in composition and typically black in color. Compared with window glass, obsidian is rich in iron and magnesium; tiny (<.005 mm) crystals of iron oxide within the glass cause its dark color. |
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Biotite Granite Location: Woodbury, VT Description: Minerals in this rock include Quartz, plagiclase, biotite, and K-feldspars. |
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Ryolite Location: Castle Rock, CO Description: is a fine-grained or glassy igneous rock chemically and mineralogically the volcanic equivalent of granite.
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Phonolite Location: Near Cripple Creek, CO Description: are fine-grained, undersaturated, intermediate igneous rocks, with or without phenocrysts, consisting primarily of alkali feldspars and feldspathoids together with pyroxenes and amphiboles, usually sodic varieties. |
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Volcanic Agglomerate Location: McCoy, CO Description: volcanic rock with clasts larger then 64mm |
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Aplite Location: Boulder County, CO Description: is a medium - to fine-grained rock (average grain size usually 1.0mm or less) with a characteristic equigranular, sugary (saccharoidal) texture. |
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Scoria Location: Near Klamath Falls. OR Description: a basalt and andesite flow |
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Rhyolite-prophyry Location: Chaffee county, CO Description: is a fine-grained or glassy igneous rock chemically and mineralogically the volcanic equivalent of granite. |
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Rhyolite Location: N/A Description: is a fine-grained or glassy igneous rock chemically and mineralogically the volcanic equivalent of granite. |
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Aporhyolite Location: Mattapan, MA Description: |
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Pegmatite Location: Portland, CT Description: are holocrystalline usually leucocratic rocks that are, at least in part, exceptionally course-grained, and in which extreme variations in grain size are wide spread. Their dominant constituents are minerals typically found in ordinary igneous rocks. |
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Syenite Porphyry Location: Pershing, CO Description: are holocrystalline course- to medium-grained intermediate igneous rocks in which the dominate mineral is alkali feldspar. |
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Monzonite Location: San Juan County, CO Description: are uncommon intermediate intrusive igneous rocks with quartz <5% and alkali feldspars: plagioclase between 35 and 65%. |
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Oil Shale Location: Garfield County, CO Description: fine-grained sedimentary rocks containing relatively large amounts of organic matter.
http://www.emdaapg.org/Oil%20Shale.htm |
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Ecologite Location: Sonoma, CA Description: the rocks name eclogite was first used by R.J. Hauy in 1822 for a "fancy rock" composed mainly of two minerals "diallage and garnet accompanied accidentally by kyanite, quartz, epidote, and lamellar amphibole. |
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Chocolate "Tennessee Marble" Location: Near Knoxville, TN Description: is a rock composed of minerals having essentially similar hardness and sufficiently dense texture to permit polishing. Scientific usage limits mineralogy to 90% carbonate (mainly calcite and dolomite) and the term is usually restricted to crystalline carbonate rock resulting in metamorphism. |
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Arkose Location: Mount Tom, MA Description: type of sandstone that is rich in feldspars.
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Argillaceous Shale Location: Rochester, NY Description: a laminated or fossile mudrock. Argillaceous describes rocks or sediments containing particles that are silt- or clay-sized, less than 0.625 mm in size. |
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Amphibolite Location: Clintonville, NY Description: are hornblende-plagioclase rocks of metamorphic origin that are widely distributed, especially in Precambrian shield areas and in younger orogenic belts. |
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Argillaceous Limestone Location: Trenton, NY Description: a sedimentary rock dominated mineralogically by calcite. Argillaceous describes sediments containing particles that are silt or clay-sized, less than 0.625 mm in size. |
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Argillaceous Sandstone Location: Description: a well cemented sedimentary rock consisting predominantly of quarts. Argillaceous describes sediments containing particles that are silt or clay-sized, less than 0.625 mm in size. |
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Mica-Augite Peridotite Location: Murfreesboro, AR Description: is an ultramafic plutonic rock containing 40-100% olivine (from peridot, French for olivine); other essential minerals include clinopyroxene; common accessory minerals are hornblende, mica, spinel, garnet, feldspar, ilmenite, and sulfides. |
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Grey Limestone Location: Chauvont, NY Description: a sedimentary rock dominated mineralogically by calcite. |
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Cherty Limestone Location: Leroy, NY Description: a sedimentary rock dominated mineralogically by calcite. This particular sample contains chert which is a hard rock, consisting primarily of silica minerals. |
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Fossiliferous Limestone Location: Description: a sedimentary rock dominated mineralogically by calcite. Fossiliferous refers to the abundance of minerals within the rock. |
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Red Sandstone Location: Potsdam, NY Description: a well cemented sedimentary rock consisting of predominantly quarts. |
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Arenaceous Shale Location: Greens County, NY Description: a laminated or fossile mudrock. |