Herkimer Diamonds are a special variety of Quartz, found in Herkimer county, New York. The deposit occurs in dolomite (silicified limestone) and is incredibly difficult to break. Fossils are found alongside Herkimers, that further indicates a low temperature crystallization. Miners use heavy sledge hammers and chizels to remove many feet of overburden, to expose the pocket layer. Herkimers were named by General Herkimer in the mid 1800's. This is a very clear, beautiful example of two inter-grown Herkimer Diamonds. It's well over 1 1/2 inches long and is very gemmy and reflective. In the larger of the two crystals, there is a substantial gas bubble trapped inside a fluid cavern that moves about 2 mms, when you angle the crystal down. The two crystals may have been reconstructed, but I see no signs of epoxy under fluorescent light.