Snowflake obsidian is a form of volcanic glass that features white or grayish “snowflake” shapes made of embedded cristobalite. These pretty patterns are not artificially added as a cheap ...

As with other forms of obsidian, rainbow obsidian is both rock and glass. However, this isn’t the same kind of glass that’s used in your nice new French doors. It’s far more badass ...

Obsidian is an example of an extrusive igneous rock. Obsidian has crystals which ... some of the minerals in the sediment harden and form a kind of cement which sticks the grains of the rock ...