Rainbow Obsidian from Mexico.
PUMI1998-2
Obsidian is formed by the rapid cooling of viscous lava that is extremely rich in silica. It has no crystal structure as it cools too fast to crystallise, a stone similar to a natural glass. When polishing a piece of this Mexican stone, we sometimes discover those lustrous layers. Those rainbow colors are caused by pyroxene's nanoparticle inclusions in the hot lava. More especially, particles of Hedenbergite. Volcano Tequila, mine of La Revoltosa in Jalisco state. And this piece is fascinating on both sides!
This unique piece has been sold...
