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Explain pegmatite is coarse grained with large crystals basalt is fine grained with small crystals and obsidian has no crystals?
Brookeevans
Crystal size in these rock types is determined by their rate of cooling. Pegmatites have large crystals due to very slow cooling. Obsidian has microscopic crystals due to almost instantaneous cooling.
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Vein of extremely large grained minerals?
pegmatite
What is pegmatite texture?
A pegmatite texture in a rock is a course-grained Igneous Rock. Granite Pegmatite is a common Igneous rock
What texture do igneous rock have when magma cools?
It can be described as aphanitic. This just means that the rock has very small, hard to see crystals. The crystals do not have time to grow large when they are exposed to the air so they cool quickly and remain small. If water is added to the melt, the texture can be described as glassy (like obsidian).
What kind of crystals are formed when liquid rock cools slowly beneath the earth's surface?
Coarse large grained crystals.
what is a type of igneous rock that cools quicklymmmmmm?
Well when an igneous rock cools quickly, it ends up being fine-grained, as there wasn't any time for large crystals to form. Examples include andesite, basalt, tuff, scoria, etc. Obsidian is also the result of lava cooling extremely quickly, to the point where no crystals whatsoever were able to form.
What igneous rock has no visible crystals?
Granite is a coarse grained igneous rock without Pyroxene.
Vein of extremely large grained minerals?
pegmatite
What is pegmatite texture?
A pegmatite texture in a rock is a course-grained Igneous Rock. Granite Pegmatite is a common Igneous rock
Is obsidian course grained?
fine grained
Is obsidian course-grained or fine-grain?
fine grained
Does obsidian a glassy rock have a large grain size or a small grain size?
Actually, obsidian doesn't have grains at all. Technically obsidian is a glass, which means it has no internal structure. When geologists refer the the grain size of a rock, they mean how big the crystals that make it up are. Since obsidian has no crystals, it therefore has no grain size.
What name is applied to a coarse grained felsic igneous rock?
pegmatite
What is the difference between coarse-grained and fine-grained?
Fine grained has larger crystals and coarse grained has smaller crystals
What is the difference between fine-grained and coarse-grained?
Fine grained has larger crystals and coarse grained has smaller crystals
A coarse grained igneous rock with no pyroxene?
Granite is a coarse grained igneous rock without Pyroxene.
Is the resulting texture of extremely rapid cooling of lava in which no crystals form?
The texture is really glassy, like obsidian.
What is a glassy grained extrusive rock?
Obsidian.
