Please im really desperate right now, and I could fail earth science D:
also between Granite diorite, gabbro, basalt, pumice, obsidian, rhyolite, andesite
gneiss, schist, marble, quartzite, and slate
also between Granite diorite, gabbro, basalt, pumice, obsidian, rhyolite, andesite
gneiss, schist, marble, quartzite, and slate
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Igneous Rocks:
Basalt, Diorite, Gabbro, Granite, Obsidian, Pumice, Rhyolite, Andesite
Sedimentary Rocks:
Conglomerate, Limestone, Sandstone, Shale
Metamorphic Rocks:
Gneiss, Marble, Quartzite, Schist, Slate
The colored band across the page gives the name of the rock. The description is underneath the band.
http://www.rockhounds.com/rockshop/rockk…
http://www.rockhounds.com/rockshop/rockk…
http://www.rockhounds.com/rockshop/rockk…
(not on the pages above)
ANDESITE
Andesite is an extrusive igneous rock, light to dark gray, sometimes with reddish to greenish hues; fine-grained, sometimes displays bubbles (vesicular texture), frequently has a brecciated texture (tuff) and sometimes contains phenocrysts of feldspar (Ca and Na rich varieties), quartz, hornblende, pyroxene, and biotite mica.
Composition:
Andesite is between about 52 and 63 weight percent silica (SiO2). Andesite crystals are composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende. At the lower end of the silica range, andesite lava may also contain olivine.
Stratovolcanoes:
Andesite magma commonly erupts from stratovolcanoes as thick lava flows, some reaching several kilometers in length. Andesite magma can also generate strong explosive eruptions to form pyroclastic flows and surges and enormous eruption columns. Andesites erupt at temperatures between 900 and 1,100 degrees C.
http://vulcan.wr.usgs.gov/LivingWith/Vol…
Basalt, Diorite, Gabbro, Granite, Obsidian, Pumice, Rhyolite, Andesite
Sedimentary Rocks:
Conglomerate, Limestone, Sandstone, Shale
Metamorphic Rocks:
Gneiss, Marble, Quartzite, Schist, Slate
The colored band across the page gives the name of the rock. The description is underneath the band.
http://www.rockhounds.com/rockshop/rockk…
http://www.rockhounds.com/rockshop/rockk…
http://www.rockhounds.com/rockshop/rockk…
(not on the pages above)
ANDESITE
Andesite is an extrusive igneous rock, light to dark gray, sometimes with reddish to greenish hues; fine-grained, sometimes displays bubbles (vesicular texture), frequently has a brecciated texture (tuff) and sometimes contains phenocrysts of feldspar (Ca and Na rich varieties), quartz, hornblende, pyroxene, and biotite mica.
Composition:
Andesite is between about 52 and 63 weight percent silica (SiO2). Andesite crystals are composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende. At the lower end of the silica range, andesite lava may also contain olivine.
Stratovolcanoes:
Andesite magma commonly erupts from stratovolcanoes as thick lava flows, some reaching several kilometers in length. Andesite magma can also generate strong explosive eruptions to form pyroclastic flows and surges and enormous eruption columns. Andesites erupt at temperatures between 900 and 1,100 degrees C.
http://vulcan.wr.usgs.gov/LivingWith/Vol…
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In conversation, most intrusive, plutonic rocks are [incorrectly] lumped into the category of "granite" (porphyritic granite, gabbro, syenite, diorite, granodiorite, etc.) These rocks form a gradation, depending upon the amount of silica and dark minerals present. True granite consists of 20-35% quartz, more than 65% total silica, and generally more K-feldspar than Na-feldspar. Total percentage of muscovite, biotite, and amphibole (typically, hornblende) can be up to about 20%.
{short description of image} Granite is formed at some depth within the earth's crust, from magma intrusions. Longer cooling times translate to larger grain sizes. For collecting, larger grain size also means better specimens. You won't find many interesting specimens in the fine-grained "microgranite" boulders that sit on the lawns in north Jersey, for example
{short description of image} Granite deposits are exposed over geologic time by weathering and erosion of the less-durable rocks that cover them. Granite does not just flow out of a volcano onto the surface; if it did, it wouldn't be granite, it would be rhyolite.
{short description of image} Granite is formed at some depth within the earth's crust, from magma intrusions. Longer cooling times translate to larger grain sizes. For collecting, larger grain size also means better specimens. You won't find many interesting specimens in the fine-grained "microgranite" boulders that sit on the lawns in north Jersey, for example
{short description of image} Granite deposits are exposed over geologic time by weathering and erosion of the less-durable rocks that cover them. Granite does not just flow out of a volcano onto the surface; if it did, it wouldn't be granite, it would be rhyolite.