Herkimer diamonds are are specific kind of quartz mined in Herkimer County, NY. While quartz is made from Silicon Dioxide, one of the must abundant minerals in the world, these specimens got their generic title from their rare double-terminated formation that gives it quite the sparkle like real diamonds. This type of formation has two naturally faceted ends due to forming in cavities, or vugs, inside clay, free-form, as opposed to on a side of a rock. Herkimer diamonds, also called Middleville diamond or a Little Falls diamond, form inside the vugs of the Cambrian-age, Little Falls Dolostone - deposited about 500 million years ago. These cavities are frequently lined with drusy quartz crystals and often are coated with a tarry hydrocarbon.
These beauties develop in fine, singles, clusters and matrix form. Though Herkimer County, New York is the location for which these crystals are named, similar crystals have been found in a other locations, including Arizona, Afghanistan, Norway, Ukraine and China, but can't quite be called "Herkimers".
Often totally clear, but frequently with fun inclusions. Shown below are crystals with, as well as inclusions of black bituminous, orange mineralized water inside, which make for bubbles that move as you turn the crystal around.
Herkimer diamonds were discovered by The Mohawk Indians and early settlers, who found them in stream sediments and when plowing fields. Amazed by there beauty, they held them in high esteem. Then they became largely recognized after workmen discovered them in large quantities while cutting into the Mohawk River Valley dolostone in the late 18th century.
Enjoyed by collectors, rock enthusiasts, and jewelers these crystals are just plain pretty.