Obsidian

Obsidian is a natural volcanic glass formed when silica-rich lava cools so rapidly that it doesn't have time to cristalize. Since it has an amorphous structure, it is not a true mineral but a mineraloid with a smooth, glassy texture and conchoidal fracture.

While black obsidian is the most common variety, other types include snowflake, mahogany, rainbow, silver sheen and gold sheen, each distinguished by unique mineral inclusions which give different optical effects.

Obsidian is a highly protective and powerful stone, believed to absorb negative energies from the surrounding environment. It helps relieve stress and mental tension and encourages self-awareness by bringing personal flaws, weaknesses, and emotional blockages into focus. It also supports confronting one's shadow aspects and accepting or reconciling with what may be difficult to face.