ROUGH FIRE AGATE STONE

This is a piece of rough fire agate.

This stone was mined in Mexico but it is found in Arizona also. The stone appears to glow inside like opal. The gem is thought to be formed when hot water saturated with silica and lava oxide invade cavities in the rock and cool. Chalcedony with iron oxide begin to grow on the surface. The iron oxide gives the basic brown color to the stone. It grows layers of silica and iron oxide. These alternating silica and iron oxide cause the brilliant fire from the stone. After the iron oxide ran out of the specimen colorless chalcedony contained to grow over it.