Rainbow Obsidian (known also as Heaven Eye) is a type of black obsidian that when highly polished and exposed to strong, bright light reveals lustrous layers, showing iridescent bands of red, blue, gold, violet, or green. The stone is made of volcanic glass, and the layers are caused by the pyroxene and magnetite's nanoparticle inclusions that shines bright when any light hits it. Rainbow Obsidian was formed when lava once cooled at different times capturing magnetite nanoparticles within these layers.
