Feature Gems & Gemology, Spring 1992, Vol. 28, Issue 1

Kilbourne Hole Peridot

This little-known source of gem-quality peridot, located in southwestern New Mexico, produces small but brilliant gems. Kilbourne Hole peridot is found in the explosion debris of a 180,000-year-old volcano, usually in elliptical "xenolith bombs." Kilbourne Hole peridot has a greater color range than the San Carlos, Arizona, material and an additional characteristic inclusion. Although the deposit is not being mined commercially, thousands of carats of gem-quality peridot have been found there.