Herkimer diamonds are natural quartz crystals found in the Leatherstocking region of New York, famous from the book The Last of the Mohicans. These stones are around 500 million years old and have 18 natural facets. They are rated seven on the Mohs hardness scale, meaning they are quite durable, tougher than most gemstones except for a few like topaz and diamonds. The Herkimer diamonds are set in fine and sterling silver, along with twisted wire hoops and ear wires made of sterling silver.