What happens to crystal if it is exposed to large amounts...?

Question

what happens to crystal if it is exposed to of very hot elements (fire, etc) for long periods of time?

Answer 1

That depends on the mineral itself. Many are unchanged, or develop cracks. Others melt and recrystallize in certain forms. Others again are chemically changed, resulting in new minerals.

Examples are marble (recrystallized limestone) and citrine quartz, which is produced when amethyst is heated strongly.