Just a few minerals make up most of the rocks we ... In this article, we'll list 30 types of rock with pictures and a brief description to help you identify them.

Minerals are typically formed when molten rock, or magma, cools, or by separating out of mineral-rich water, such as that in underground caverns. In general, mineral particles are small ...

A close-up photo taken by the Curiosity rover shows pure yellow sulfur crystals within a rock. NASA’s Curiosity rover ran over a rock on Mars in late May. That’s par for the course on the red ...