Obsidian is one of the sharpest naturally occurring materials. It breaks with a conchoidal fracture which is a characteristic of most types of glass.
An advisor to Queen Elizabeth I, who used a black obsidian mirror, believed it enabled him to communicate with the spirit world.
The mirror, housed in the British Museum, was designed by the Aztecs in Mexico.
Obsidian is best known for being black but occurs in different colours and with various inclusions and sheens.
Obsidian is a non-crystalline solid that forms when lava cools and solidifies.
Classed as a rock, not a mineral, obsidian is correctly known as a mineraloid.
MOTHER OF PEARL
