"Herkimer Diamonds" are an extremely clear quartz with terminations (points) at each end. Their clarity, small size and light qualities give them the diamond name.
Their growing conditions caused the crystals to form slowly which led to high transparency and clarity. Most of the crystals are very small.
They can be found around Herkimer County, New York where there a few mines and you-dig operations.
Below are micro images of a Herkimer diamond at around 100x magnification. This crystal is approximately 1/4 inch long (6.35 mm). The black background is a regular cotton handkerchief which will give some perspective on the zoom.
