What’s so special about Herkimer diamonds? Firstly, although “diamond” is in the name, Herkimer diamonds are actually a type of quartz found by the Mohawk River in Herkimer, NY. There are also many specimens extremely similar to Herkimer diamonds that are sourced from Arizona, Afghanistan, Norway, Ukraine, and China. Wherever they come from, their name alludes to their incredible clarity and visual resemblance to diamonds. But there is much more to the story; let’s put on our figurative headlamps and peer a little deeper into the rock.r figurative headlamps and peer a little deeper into the rock.
One major reason Herkimer and Herkimer-like diamonds are so remarkable is because they are naturally double-terminated. Normally when we see double-terminated points for sale in crystal shops, they are carved by human hand rather than natural processes. But with Herkimer and Herkimer-like diamonds, Mother Nature did that work herself! The crystals formed this way because they grew very slowly with little to no contact with their host rock, the Little Falls Dolostone. The quartz is thought to have formed during the Carboniferous period (about 300-360 million years ago). Herkimer-like diamonds also formed in dolostone, but their process of growth was different from true Herkimers. For instance, while specimens from Herkimer County came from freshwater and marine sediments, specimens from Pakistan emerged from seawater and rock bodies.
Another noteworthy aspect of true Herkimer diamonds is that they are not a recent discovery. By the time European settlers found the quartz in the late 18th Century, the indigenous Kanyen'kehà:ka people (known in English as the Mohawk people) had already known and valued it for hundreds of years. They collected the crystals from stream sediments and plowed fields, then used them in spiritual ceremonies, healing practices, amulets, tools, and trades with other tribes. (Note: this author regrets to report that she cannot find the specific Kanyen'kehà:ka word for the crystals themselves, but she will continue researching for future reference.) The name “Herkimer diamond” was not used until well after European settlers came upon the crystal. Its home region of Herkimer County is named for Revolutionary War military officer Nicholas Herkimer.
Today, Herkimer and Herkimer-like diamonds remain objects of immense fascination. These double-terminated quartz points may be small, but they are stunningly beautiful. Specimens are nearly always transparent and range from colorless to smoky in color. They contain a fantastic variety of inclusions, the most common of which are particles of solid hydrocarbon materials. The crystals may also include saltwater, liquid petroleum, carbon dioxide, calcite, dolomite, pyrite, sphalerite, and more. As with all crystals and stones, no two Herkimer diamonds are alike; each embodies its own unique expression of natural minerals waiting in the dolostone.
