“Herkimer diamonds” is the name given to the doubly terminated quartz crystals found in Herkimer County, New York and surrounding areas. Examples of these crystals are shown in the photos on this page.

Herkimer diamonds have the typical crystal habit of quartz; however, however, instead of having a termination on one end they are doubly terminated. This is a result of the crystals growing with very little or no contact with their host rock.

Doubly terminated crystals are very rare. This is what makes “Herkimer diamonds” amazing creations of nature. They are very popular with mineral collectors.