Three Herkimer quartz crystal specimens. Sizes & descriptions:
- A 3.5x2x.75" piece of dark dolomite with a clear 6 mm Herkimer set in a vug. Photos in the first group of pictures below.
- At 4.75x2.5x2.5" it's a nice solid matrix piece with a 12+ mm tabby crystal jutting from a tight vug. On the other side is another tight vug with two blemished Herks.
- The largest specimen, 6x7x3.5", pictured above, is the best of the three. Several pockets of dog's tooth and druse crystal are present. Another vug, lined with black hydro carbon holds a quality, 13 mm, double terminated water clear Herkimer quartz crystal.
Herkimer quartz crystals were formed by tremendous heat 300-500 million years ago beneath a shallow sea bed of the rock dolomite, now New York state. The dolomite matrix began as limestone and calcite rock, and while still under water, magnesium was added. This new addition created the sedimentary rock called dolomite. Pockets and vugs within the dolomite were filled with fluid rich in silicon dioxide, or quartz, providing the material to allow the clear crystals to form. One explanation as to the double terminations points of Herkimer's is that the fluid filled pockets allowed them to form freely, providing the opportunity to terminate on both ends. Another explanation to the double termination's is silica has no attraction to the dolomite rock and avoids attachment to it.
These are three quality Herkimer quartz crystal in dolomite specimens. Wish they would have photographed better, the pictures don't do them justice.