Snow Flake Obsidian Ore On White Background. Stock Image

Pure obsidian is usually dark in appearance, though the color varies depending on the presence of impurities. Iron and other transition elements may give the obsidian a dark brown to black color. Very few samples are nearly colorless. In some stones, the inclusion of small, white, radially clustered crystals of cristobalite in the black glass produce a blotchy or snowflake pattern snowflake obsidian. Obsidian may contain patterns of gas bubbles remaining from the lava flow, aligned along layers created as the molten rock was flowing before being cooled. These bubbles can produce interesting effects such as a golden sheen sheen obsidian. An iridescent, rainbow-like sheen rainbow obsidian is caused by inclusions of magnetite nanoparticles.