Like other igneous rocks, the glossy glass originates from molten rock that has been spewed out from the bowels of the Earth via volcanoes. Before we get into the snowflakes, obsidian is formed ...

Obsidian has crystals which are so small that they are impossible to see without a microscope. Intrusive igneous rocks are formed by magma that has cooled slowly, deep underground. Granite is an ...

This molten earth origin is what classes rainbow obsidian as an igneous rock. Lava destined to become obsidian cools rapidly once on the surface and, thanks to its viscous nature, is also below ...