Golden Obsidian Natural 6mm Round Large Hole Beads - 8 Inch Stone Type_Boulder Opal rainbow effect of light refracting

rainbow effect of light refracting off of the air bubbles inside of the stone

Red Botswana Agate displays highly defined parallel banding

a 19th-century German professor of chemistry and mineralogy

It is often thought of as an all-black stone

Golden Obsidian Natural 6mm Round Large Hole Beads - 8 Inch Stone Type_Boulder Opal rainbow effect of light refractingGolden Obsidian is a naturally occurring volcanic glass, shiny black with a golden sheen. Obsidian is produced when lava erupts from a volcano and cools rapidly with minimal crystal growth. It is sometimes used for scalpel blades in cardiac surgery, as Obsidian can be formed into a blade many times sharper than steel surgical blades. Approximate Hole Diameter: 2mm