Herkimer, New York

The village of Herkimer sits in the Mohawk Valley and carries the name of Nicholas Herkimer, the son of German immigrants who commanded American forces at the Battle of Oriskany in seventeen seventy-seven, one of the bloodiest engagements of the Revolutionary War. But the county bears another kind of fame as well: the Herkimer diamond. Found in the dolomite rock of the Mohawk Valley, these are not diamonds at all but double-terminated quartz crystals that grew in cavities of dolomite about five hundred million years old, so clear and well-faceted that early settlers could not believe they were not gemstones.

Workers quarrying the valley's dolomite in the late seventeen hundreds began turning them up in abundance, and the crystals eventually took the name of the county where they were most plentifully found. They are still mined today, and collectors travel from across the country to dig for them near the village of Middleville.