Agate Gemstone is one variety of chalcedony which is a semi-precious natural gemstone discovered so far only in certain areas of “central and northern Mexico and the southwestern United States (New Mexico, Arizona, and California)”. The fire agates were formed during a period of volcanism when hot water, saturated with silica and iron oxide, repeatedly filled cracks and bubbles in the surrounding rock. Fire agates have beautiful iridescent rainbow colors, similar to opal, with a measurement of hardness on the Moh’s scale of between 5 and 7 which reduces the occurrence of scratching when polished gemstones are set in Jewelry.