Golden Obsidian Natural 6mm Round Large Hole Beads - 8 Inch Stone Type_Boulder Opal after its type locality

after its type locality

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

a 19th-century German professor of chemistry and mineralogy

To create Cherry Quartz

it lightens because of further weathering and becomes Malachite

Golden Obsidian Natural 6mm Round Large Hole Beads - 8 Inch Stone Type_Boulder Opal after its type localityGolden 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