2007-05-13 16:31:38 · 5 answers · asked by Ray G 1 in Science & Mathematics ➔ Earth Sciences & Geology
Aphanitic is the term used for volcanic rocks like obsidian that have a microcrystalline structure.
Aphanitic (′af·ə′nid·ik):
(petrology) Referring to the texture of an igneous rock in which the crystalline components are not distinguishable by the unaided eye.
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2007-05-13 17:11:49 · answer #1 · answered by Now and Then Comes a Thought 6 · 3⤊ 2⤋
It's a trick question. Obsidian is a volcanic glass and has no grain structure.
2007-05-13 16:58:11 · answer #2 · answered by squeezie_1999 7 · 2⤊ 3⤋
Obsidian has no granular texture at least not visible to the naked eye .... under an electron scope there may be some microgranular structures . but certainly these would not qualify as grains... when obsidian breaks it chips into tiny flakes ...which are usually very sharp ...
2007-05-13 16:39:00 · answer #3 · answered by ccseg2006 6 · 2⤊ 2⤋
What grain size? Being volcanic glass it has no crystal growth to speak of and isn't really even a mineral.
2007-05-13 16:35:14 · answer #4 · answered by Critters 7 · 1⤊ 4⤋
bs
2015-03-12 10:50:09 · answer #5 · answered by latchezar 1 · 0⤊ 0⤋