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

from deep oranges to creamy off-white tones

this opal variety is characterized by their dark base tone

Red Tiger Eye is actually Brown Tiger Eye which has been heat treated to bring out the red color

A mixture of hydrocarbons

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)