Obsidian is a form of volcanic glass which is released from volcanic activity. It forms no crystalline structure as it cools very rapidly once emitted from the volcano. As a result this form of quartz is technically not a crystal.
Obsidian can come in a number of forms including Rainbow, gold sheen, purple sheen, mahogany, snowflake and Apache tears. The Rainbow and the obsidians with sheen have colours due to the refraction of light in and on the surface of pieces of black obsidian.
Obsidian has detoxifying properties. Working with Obsidian brings feelings of support and protection.
Obsidian will work over longer periods of time to seek out imbalances, both emotional and mental, which it will then highlight and actively begin to remove. This process can leave the user a bit emotionally or mentally tender during and immediately after the work. Be gentle with yourself when working with obsidian, this mineral will get to the real issues lying beneath the surface.