Fossil Coral 12mm Coin 8-Inch Green Quartz an opaque silicon dioxide mineral

an opaque silicon dioxide mineral and form of microcrystalline Chalcedony

and because its hardness has made the stone perfect for beads and cabochons

Sometimes called the "Black Prince's Ruby" for its role in the English crown

milky white to pale yellow in color

First described in 1881

Fossil Coral 12mm Coin 8-Inch Green Quartz an opaque silicon dioxide mineralFossil Coral is the prehistoric fossilized remains of the invertebrate reef builders that live in tropical oceans. Silica rich waters create hardened deposits that preserve coral skeletons, resulting in fossils that are chalk white, tan, gray, and brown as well as pink, red and yellow orange.