Opal is a hardened silica gel that contains 5 to 10 percent water. Its opalescence is caused by refracting light off of silica spheres within. Australia, Japan, and the United States are major sources.
Known as the "Queen of Gems," opals have long been a symbol of loyalty and hope.
Opal is the birthstone for October.
SS Black Spinel and Ethiopian Opal Beaded Necklace