Ants delivering small mineral particles to the surface is not unique to Arizona. It is known in many parts of the world. In a few instances, ant hill minerals have been used as a prospecting tool. In prospecting for diamonds, geologists use “indicator minerals” to determine if they are on or near a kimberlite pipe – the host rock of…

A few areas in Arizona are well known for ant hill garnets. These are beautiful bright red chromium pyrope garnets with a very high color saturation. The Native Americans discovered them long ago and marveled at their color and beauty. They regarded them as special and sometimes sewed them into ceremonial rattles or gave them…

Some gemstones derive a large portion of their appeal because they are found in an unexpected locality or have an unusual origin. “Ant hill garnets” are one of the more interesting of these “novelty gems.” They are called “ant hill garnets” because they are found on and around the margins of ant hills. The ants encounter the garnets while…