Obsidian 8x10mm Triangle Cut Faceted Puff Oval - 15-16-Inch Dendritic Black Opal The shell is often found

The shell is often found naturally polished with a green or brown spiral on one side and a white "eye" on the other

A mixture of hydrocarbons

this semi to precious variety of quartz is found in many locations around the world

white or brown

orange and rust are due to traces of hematite within the stone

Obsidian 8x10mm Triangle Cut Faceted Puff Oval - 15-16-Inch Dendritic Black Opal The shell is often foundEssentially a volcanic glass, Obsidian ranges in color from opaque black, to green, brown, mahogany, black with rainbow colors, black with snowflake patterns, black with a golden sheen, and translucent black (Apache Tears)