What on Earth Is Herkimer Diamond?

Herkimer diamonds are double-terminated, naturally faceted quartz crystals first found in Herkimer County, New York. Despite the name they are every inch quartz, with a Mohs hardness of 7.5 rather than a diamond's 10. This guide covers their properties, history and lore; for stock, see our Herkimer diamond collection and double terminated points.

Herkimer diamonds belong to the quartz family, one of the most abundant mineral groups in the world, which comes in many varieties, shapes, colours and sizes. Herkimers are the rare type prized by gem collectors, and they may carry the name (and, somehow, the look) of the world's most popular gem, but they are quartz.

Here is a closer look.

The Physical Properties of Herkimer Diamond

The most salient characteristic of a Herkimer diamond is its double terminations. And being a type of quartz, it shares the same set of physical properties with other quartz varieties.

Herkimer diamonds are often transparent and have a colourless to smoky colour. They also occur in clustered or intertwined crystal growths, often as tiny crystals (1 long) attached to larger crystals.

They are usually included with various minerals, the most common of them are hydrocarbon minerals. The presence of these minerals produces microscopic to visible particles in the crystal.

An abundance of hydrocarbon minerals can give a Herkimer diamond a rather smoky colour. Liquid inclusions in the form of petroleum and salt water can also be present in the crystal. Some crystals can be included with dolomite, calcite, pyrite, and sphalerite.

Why is it called a diamond? It is because the crystal has naturally formed facets on its terminations. Also because it looks as brilliant and attractive as a diamond when polished. A true diamond is rated 10 on the Mohs hardness scale, while a Herkimer quartz is 7.5.

Herkimer crystals are used to make earrings, necklaces, and bracelets.

The History of Herkimer Diamond

These unique quartz crystals were first seen in Herkimer County in New York almost 500 million years ago.

It is said that these crystals were discovered at the bottom of a shallow sea where they solidified inside sedimentary stones called dolostones (dolomite and limestone) together with pyrite and silicon dioxide.

Over time, sediments buried the stones when the temperatures increased.

This resulted in thermal splitting which caused the dissolution of molecules that had been holding the quartz mineral. Then the quartz eventually came out of the solutions slowly and produced the Herkimer diamonds we know today.

Some anecdotes state that Native Americans discovered the crystals in the 15^th century in water streams. Fascinated by the crystals' pointed edges, the Mohawk Indians used the Herkimer diamonds as tools and ornaments.

Today's Herkimer supplies are mined in Arizona, Afghanistan, China, and Norway. However, large-scale mining for commercial Herkimer is done only on occasions. It is performed through small-scale mining (i.e., pocket mining using crowbars, heavy chisels, and sledgehammers) as it doesn't require deep excavation.

The Lore of Herkimer Diamond

There is no information surrounding the folklore of Herkimer diamonds. But the crystal is thought to vibrate if you wear/carry it and the person you are speaking to is dishonest.

The Metaphysical Properties of Herkimer Diamond

In crystal lore, Herkimer diamonds are linked with clarity and with clearing the feel of a space, which is why people place them in homes and workplaces.

Some people use one in a crystal grid in the home, bedroom or meditation space as a symbol of clarity and calm.

When used in the workplace and other competitive environments, Herkimer crystals are traditionally linked with positive energy, prosperity, and achievement.

They are also traditionally linked with study and research, and with wise spending in business.