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H is for Herkimer Diamond

Updated: Jan 6, 2022

For our eighth instalment in our series of A-Z Gemstones Uncovered, we will be covering the beauty known as the Herkimer Diamond. Spoiler alert! Herkimer Diamond aren't actually Diamonds at all!

So first and foremost, what is a Herkimer Diamond?

"Herkimer Diamonds" is the name given to a unique form of double-terminated quartz crystal found in Herkimer County, New York and surrounding areas. The name Diamond was given based on this crystals clarity and natural faceting.

Now that's cleared, let's delve into their history ...

Herkimer Diamonds became well-known after workers discovered them in large quantities while cutting into the Mohawk River Valley dolostone in the late 18th century.

Occasionally you'll hear Herkimer Diamonds referred to as "Little Falls Diamond" or "Middleville Diamond", these names signifies the villages originally discovered from within Herkimer County.

Historical texts suggest the discovery of these stones goes back even further than the 18th century, with Native Americans and early settlers discovering this stone around the 15th century in water streams. Native Americans, particularly the Mohawk Indians who resided in this area, greatly respected and admired this stone, using them to make tools, on amulets and trading them with other tribes. They supposedly even referred to them as 'spirit stones’. However, interest in them began to dwindle when European glass beads arrived in the States during the early 1600s.

So, let's get into the formation of these "diamonds" ...

Herkimer Diamonds began forming approximately 500 million years ago. Over millions of years, layers of mineral and organic matter built up to create the sedimentary rock known as Dolostone (Dolomite and Limestone combined). The organic material such as plants and sea life would routinely perish, resulting in natural gasses forming and creating pockets within the sedimentary stone. As you can imagine, over the years, these layers would increase exponentially creating an increase in heat and pressure along with them. As time went on, quartz, carbon elements and other compounds would form and transform, eventually creating the beautiful Herkimer Diamond.

Due to their formation in pockets, Herkimer Diamonds do not have an attachment to their host bedrock, causing them to form double-terminated points with 18 facets.

Their silica-rich composition gives them greater clarity than other crystals. They are often found clear, however, they can also be cloudy, smoky and contain impurities. The impurities most commonly found, although rare, are known as phantom and fluid impurities. In phantom impurities, Herkimer Diamonds can be found with visible crystals inside them. These crystals tend to be the same type but are instead coloured. In fluid impurities, Herkimer Diamonds can be found with little air bubbles or pockets containing liquid. This liquid tends to be water but is sometimes methane or oil. In rare cases, these fluids will move within their pocket as the stone is turned or shaken. Black inclusions tend to be anthraxolite, whilst yellow ones are usually petroleum.

Herkimer Diamonds sit slightly higher than Quartz on the Mohs Scale. Quartz tends to have a 7 in hardness, whereas these stones measure at 7.5. Comparatively, real Diamonds are at the top of the scale measuring at 10.

Where are Herkimer Diamonds found?

True Herkimer Diamonds are found in one place: Herkimer County, New York. There are a handful of mines in this area, both owned by the State and privately.

"Herkimer" Diamonds are found in other locations, such as Arizona, Afghanistan, China, Norway and Ukraine. However, they are not "true" Herkimer Diamonds, they just share the same appearance. Think of "Champagne" and "Sparkling Wine" or "Parmasean" and "Hard Cheese" although there are not any laws strictly prohibiting it. As the Herkimer name relates directly to the location, it makes sense you can't get true Herkimer Diamonds elsewhere.

5 fun facts about Herkimer Diamonds:

  • Legend has it that Herkimer Diamonds got their namesake due to being “discovered” by general Nicholas Herkimer during the war. He thought he found actual diamonds in New York and hoped to fund the war with his discovery however his hopes were shattered when they were discovered to be quartz - hence the name Herkimer Diamonds was born.

  • Herkimer Diamonds are mostly mined on a small scale without any extensive machinery or excavation being required. Therefore these stones have become a popular choice for alternative diamonds due to their similar appearance and conflict-free nature.

  • Herkimer Diamond KOA Resort is owned by Dr Renee Scialdo Shevat, who is thought to be the only female mine owner in the world. In 1979, Shevat's parents purchased the mine as a retirement hobby, unaware of the international awareness and intrigue over the Herkimer Diamond. Now owned by Shevat, she runs the mine with her father. The resort is open to the public, allowing them to find these rare crystals themselves.

  • In 2019, sales of the Herkimer Diamond soared after Meghan Markle, the Duchess of Sussex, was spotted wearing a bracelet, earrings and rings that featured the unique Herkimer diamonds to Princess Eugenie's wedding in Windsor. The pieces were designed by Pippa Small and were sourced from Renee Scialdo Shevat's mine!

  • Herkimer Diamonds are said to be very high vibrational stones that have become known as “The Stone of Attunement”. Its energies supposedly work to put you at ease when in uncomfortable environments and guide you in the right direction in tough situations.


If you enjoyed this post, check out the rest in our series: A-Z Gemstone's Uncovered.

We'd love to hear your thoughts, what's your favourite thing about Herkimer Diamonds or which gemstone would you like us to feature next! Comment below, like or share this post.

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