Wow, what an incredible adventure! I recently returned from a beautiful Herkimer Diamond mining trip in Herkimer County, New York with my friends and fellow jewelry artists, Trista Bonnett and Valerie Heck Esmont.  Herkimer is home to the world-famous Herkimer Diamonds.  A few of my favorites finds from our treasure hunting are pictured above.

What are Herkimer Diamonds?

Herkimer Diamonds are stunning naturally faceted, doubly terminated, water clear quartz crystals found within dolomite rock. While most are flawless, some of these gems have rainbow inclusions, air bubbles, or black carbon and golden orange iron deposits.  Herkimer Diamonds are special because they come directly out of the ground in the shapes you see, they are not faceted by gem cutters. Similar to geodes, Herkimer Diamonds grow over the course of hundreds of millions of years in small cavities called “vugs” containing one or two crystals or larger cavities, often several feet across, known as “pockets” that can contain a few dozen to hundreds of crystals. Herkimer Diamonds’ double terminations (pointy ends) are incredibly rare within the world of gemstones and occur as a result of the crystals growing in very little contact with the surrounding dolomite rock. Most quartz crystals grow attached to the surrounding rock or stone and have only one termination or point. 

History of Herkimer Diamonds and How They Got Their Name

Large deposits of Herkimer Diamonds, that to the untrained eye look and sparkle like real diamonds, were “first” discovered in the late 18th century by workers cutting into the dolomite rock in the Mohawk River Valley throughout Herkimer County, New York. The county was named after Revolutionary War General Nicholas Herkimer; thus, the name Herkimer Diamonds. Prior to the early settlers, the Mohawk Indian tribes, native to the area, named the region “Kanyenka” meaning “Place of the Crystals” and they are known as “The People of the Crystals.”

Deposits of doubly terminated quartz crystals are also found in Arizona, Arkansas, Afghanistan, China, Norway, and Pakistan, but only the crystals mined in Herkimer County, New York can authentically be called Herkimer Diamonds. A really amazing quality of the doubly terminated quartz crystals from Pakistan is they often have petroleum inclusions, known as golden enhydros or enpetros, that will fluoresce a beautiful blue-green color under UV light. (I’ve incorporated several of them in my Voyageuse Collection which you can take a closer look at here.)

Where to Find Herkimer Diamonds

Unlike other gemstones that require the extremely dangerous work of tunneling deep underground, Herkimer Diamonds are found above ground in quarries.  Camping is the best to way stay if you want to be close to the Herkimer Diamond mines. Valerie, Trista and I planned this trip for over a year and wanted comfy environmentally responsible accommodations, so we stayed at a solar-powered deluxe cabin at the Herkimer Diamond Mines Kampgrounds Of America (KOA) Resort on Route 28 in Middleville, NY. While roughing it in a tent can be fun and we’re not ones to shy away from getting dirty, at the end of the day we’re still ladies and want real beds and private hot showers, so our solar powered cabin was a great cozy choice.

There are 2 mines across the street from the KOA Resort, the World-Famous Herkimer Diamond Mines, owned and operated by the Scialdo family (who also own the KOA Resort) and The Ace of Diamonds Mine and Campground owned and operated by Ted, Anita and Anna-Jane Smith.  Both are open from early April through late October each year and charge a modest admission fee of $10-15 for a full day of mining; whatever Herkimer Diamonds you find, you keep.  The World-Famous Herkimer Diamond Mines is the more touristy and little kid friendly location of the two offering on-site restaurants, and activity and artisan centers.  Ace of Diamonds Mines is a massive fully functional Herkimer Diamond mining operation great for serious collectors and families with responsible children.  Fresh material from the heavy equipment mining in other areas at Ace of Diamonds is dumped around the quarry section of the mine on a regular basis and great for finding larger sized crystals.

The Smith family has extensive knowledge of a wide variety of gems and minerals and also offer Guided Mining experiences where for $1,900 they’ll locate a pocket prior to your arrival, then provide you with power tools and assistance in opening the pocket containing dozens to hundreds of Herkimer Diamonds. (A mining experience like this is definitely on my bucket list!) During the off-season, the Smiths prepare their inventory of jewelry grade and collector size gems found at their property for the Tucson Gem Shows.  Many of these shows are open to the public, so if you’re heading to Tucson in February next year be sure to check them out.

4 Ways to Mine for Herkimer Diamonds

As with all treasure hunting, the secret is to know where to look. At both of the mines mentioned above, a wall of dolomite is exposed and significant amounts of broken rock from gravel size pebbles to small boulders line the quarry floor.

Surface Mining

Success at finding Herkimer Diamonds can be had just by walking around and searching the surface of rock rubble and surrounding soil for loose crystals. We found several nice sized and tiny Herkimer Diamonds this way; it’s almost as if the gems found us! This is also the safest prospecting method, especially if you’re bringing kids to the mines.

Sluice Mining

Taking surface mining one step further, you can shovel a bunch of soil and smaller rock rubble into buckets, we recommend the 5-gallon size, then, haul it to the sluice and wash it in large pie pan size screens of various sizes (similar to mesh colanders you might have in your kitchen), and then sort through it for crystals.  The sluice is a long trough with running water that washes away dirt and sand so you can see the Herkimer Diamond crystals more clearly against the darker rock debris.  Working as a team we found the majority of our crystals this way.  Garden tools including trowels and hand rakes are great for this method. Sluice mining is also ideal if you can spend several hours at the mines and are interested in finding jewelry sized crystals. 

Find and Break Prospecting

If you have more time at the mines, finding vuggy pieces of rock and breaking them open with a rock hammer is a good way to find larger Herkimer Diamonds.  Most of the time vugs will be empty, but if you’re lucky, a vug will contain one or a couple of crystals. If a rock doesn’t break open after a few strikes with your hammer, it probably won’t open, so move on to another rock. While persistence and patience are must have virtues in gemstone mining, continuing to wail away at a rock hoping it opens just sends rock shards flying in all directions which is dangerous to you and others working near you.  Safety goggles or a full-face shield are MUST HAVE tools for this type of prospecting.

Pocket Prospecting

Pocket prospecting is the best method for finding larger quantities or very large sized Herkimer Diamonds. This requires INTENSE physical labor and a significant amount of time, patience and knowledge of how to break extremely strong dolomite rock, so unless you’ve splurged on a Guided Mining Experience at Ace of Diamonds Mine, plan on spending a week to several weeks at the mines. You’ll need long metal handle sledgehammers, wedges and pry bars (power tools are NOT permitted at the mines mentioned in this article.) Safety equipment, including ear protection, knee pads, safety goggles or full-face shields are all absolute MUST HAVES for this kind of work. 

The wedges, pry-bars and hammers are used to exploit the natural fissures in the rock. One begins by placing a wedge in a fissure and then tapping it in a few inches with a sledgehammer, more wedges are added as needed.  This puts pressure deep into the dolomite rock and breaks large sections of it free from the quarry wall. If you’re lucky, you’ll find a pocket that could contain dozens to hundreds of single perfect crystals in all sizes and stunning crystal clusters. 

In addition to your hand tools, having some form of sun protection like a canopy or EZ-Up tent for shade will make your pocket prospecting at the mines more comfortable. You’ll also want heavy duty tarps to cover your work area, called a claim, to protect it from rain and nosy miners when you’re not working.  There is an honor code among miners and everyone looks out for one another.  If someone has claimed a spot don’t go poking around under their tarps and scavenging off of their hard work when they’re not around.  

Additional Tools for Herkimer Diamond Mining

In addition to the tools mentioned for the above mining methods, you’ll also want to have the following:

• Sturdy shoes or hiking boots with good traction and ankle support

• Sun hats and lot of sunscreen

• Plastic containers for storing and sorting your new-found treasures (these are much easier to use than plastic baggies)

• Heavy duty work gloves

• Knee pads

• Outdoor clothes you don’t care about (mining is grimy, sweaty work and if you’re climbing around on rock piles tears and stains are likely)

Rewards Greater than Gems

There’s nothing like learning by doing. We began our mining adventure by spending one morning at the World-Famous Herkimer Diamond Mines and after finding mostly small crystals, we moved on to Ace of Diamonds Mine for the rest of that day and the day after. Studying gems and minerals for years I knew gemstone mining required moving and sifting through MASSIVE amounts of dirt and rock to find precious bits of sparkle. To put myself through the experience of physically moving, sluicing and sorting pounds and pounds of rock and dirt in pursuit of said sparkle is a level of knowing and connecting with the raw materials for my jewelry designs in a way that I still can’t quite describe. 

Working as a team, my amazing friends Valerie, Trista and I navigated jagged and often unstable rocky terrain to prospect through about a 1/2 ton of material via 5-gallon bucket after bucket in search of Herkimer Diamonds for our personal collections and creative work. Our prize after 2 days at the mines representing about 40 hours of our combined labor, is an impressive haul of Herkimer Diamonds from tiny perfect crystals to a 280+ carat stunner and a deeper bond in our “sister”-friendship far more valuable than any gemstone.

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