I'm studying minerals..I understand that if molten rock cools slowly undergound, then large mineral cystals start forming. AND if that rock cools quickly at the surface, small cystals form. My ? is ..sometimes rock has both large and small mineral crystals ..how can that be explained?
thanks for responding..Kira G.
science - Ms. Sue, Wednesday, January 23, 2008 at 5:45pm
The rocks with both small and large crystals is probably a conglomerate rock. Check this site for information.
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