Herkimer Diamond Mining Guide: How to Find Quartz Crystals in Herkimer, NY
A selection of Herkimer Diamond Quartz Crystals mined by jewelry designers, Michelle Pajak-Reynolds, Valerie Heck Esmont and Trista Bonnett at the Ace of Diamonds Mine in Middleville, New York, in September 2019. Photo credit: Michelle Pajak-Reynolds
An Unforgettable Gem-Hunting Adventure
What an incredible adventure! I recently returned from a Herkimer Diamond mining trip in Herkimer County, New York, with my dear friends and fellow jewelry artists, Trista and Valerie. Nestled in the Mohawk Valley, Herkimer is home to the world-famous Herkimer Diamonds—brilliant quartz crystals that sparkle like true diamonds. A few of my favorite finds from our treasure hunt are pictured above.
What are Herkimer Diamonds?
Despite their name, Herkimer Diamonds aren’t diamonds at all—they’re stunning, naturally faceted, doubly terminated quartz crystals found in dolomite rock. Their natural brilliance comes straight from the earth—no gem cutter required.
Appearance: Water-clear, with occasional rainbow inclusions, air bubbles, or traces of carbon and iron.
Formation: They grow over hundreds of millions of years in cavities called “vugs” and larger “pockets” that can hold dozens to hundreds of crystals.
Unique Feature: Most quartz crystals have a single termination, but Herkimer Diamonds often form with two pointed ends, making them exceptionally rare.
A single Herkimer Diamond quartz crystal inside a “vug” within a small piece dolomite rock found at Ace of Diamonds Mines in Herkimer County, New York. It takes hundreds of millions of years for Herkimer Diamonds to grow inside these small cavities. Photo credit: Trista Bonnett
History of Herkimer Diamonds and How They Got Their Name
Herkimer Diamonds were first discovered in the late 18th century when workers cut into dolomite rock in New York’s Mohawk River Valley. Their uncanny resemblance to real diamonds gave them their famous name.
Origin of the Name: Herkimer County was named after Revolutionary War General Nicholas Herkimer.
Indigenous Roots: Long before European settlers, the Mohawk people called the region Kanyenka, meaning “Place of the Crystals,” and referred to themselves as “The People of the Crystals.”
Although similar quartz crystals are found in Arizona, Arkansas, Norway, Pakistan, and beyond, only those from Herkimer County, NY, can be authentically called Herkimer Diamonds. Some varieties from Pakistan even contain golden petroleum inclusions (enhydros) that fluoresce blue-green under UV light—several of which I’ve incorporated into my Voyageuse Collection.
Detail of the golden enhydro quartz crystal in Michelle Pajak-Reynolds's Voyageuse Collection Desma pendant fluorescing under UV light. Photo courtesy: Benjamin Guttery/Third Coast Gems
Where to Mine Herkimer Diamonds
Unlike many gemstones buried deep underground, Herkimer Diamonds are found at the surface in open quarries—making them much more accessible for collectors and adventurers alike.
Best Places to Mine
World-Famous Herkimer Diamond Mines – Family-friendly, with restaurants, activity centers, and artisan shops.
Ace of Diamonds Mine & Campground – A large-scale mining operation for serious collectors, known for fresh dumps of rock and the possibility of larger finds.
Both mines are located across from the KOA Resort in Middleville, NY, which offers cozy accommodations like solar-powered cabins. Perfect if, like us, you love adventure but still want hot showers and real beds after a long day of digging!
Herkimer Diamond KOA Resort Solar Powered Deluxe Cabin. Photo Credit: Michelle Pajak-Reynolds
Entrance to the mining area at the World-Famous Herkimer Diamond Mines in Herkimer County, New York. Photo credit: Michelle Pajak-Reynolds
View of Ace of Diamonds Mines from atop a pile of fresh rock rubble and looking down over the sluice and work tables. Photo credit: Michelle Pajak-Reynolds
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.
Sometimes the gems find you! This nice sized Herkimer Diamond was just sitting in the soil near the top of a rock pile. Photo credit: Michelle Pajak-Reynolds
2. 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.
A selection of freshly mined Herkimer Diamonds and calcite specimens found at Ace of Diamonds Mine sit in a sluice screen in preparation for cleaning and classifying. Photo credit: Trista Bonnett
Getting dirty pays off! Jewelry designer Michelle Pajak-Reynolds finds a few tiny perfect Herkimer Diamonds via sluice mining at Ace of Diamonds Mine in Herkimer, New York. Photo credit: Michelle Pajak-Reynolds
A nice selection Herkimer Diamond crystals and calcite specimens found after a few hours of sluice mining at the Ace of Diamonds Mine in Herkimer, New York. Photo credit: Michelle Pajak-Reynolds
3. 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.
Jewelry artist Valerie Heck Esmont uses the find and break method to prospect for Herkimer Diamonds at the World-Famous Herkimer Diamond Mines in Herkimer County, New York. Photo credit: Michelle Pajak-Reynolds
4. 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 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)
More Than Just Gems: The True Rewards
We spent two days mining—about 40 hours of combined labor—prospecting through nearly half a ton of rock and soil. Our haul ranged from tiny perfect crystals to a breathtaking 280+ carat specimen.
But the real treasure was something greater than gemstones: deepening our bond as friends and fellow artists. Mining Herkimer Diamonds connected us to the raw materials that inspire our jewelry designs and reminded us of the beauty of shared adventure.
Herkimer Diamonds may sparkle with light, but it’s the memories made while mining them that shine the brightest.
Jewelry artist Michelle Pajak-Reynolds shovels dirt and small rock rubble into a 5-gallon bucket in preparation for sluice mining at the Ace of Diamonds Mines in Herkimer County, New York. Note the various tarps protecting other miners’ pocket prospecting claims along the quarry floor and wall. Photo credit: Trista Bonnett
Well worth the effort! Hundreds of carats of Herkimer Diamonds mined at the Ace of Diamonds Mine in Middleville, New York. Photo credit: Michelle Pajak-Reynolds
Sweaty, sunburnt, sore and smiling! Jewelry designers and friends (left to right) Michelle Pajak-Reynolds, Valerie Heck Esmont, and Trista Bonnett after 2 days of mining for Herkimer Diamonds at Ace of Diamonds Mine in Middleville, New York. Photo credit: Fellow miner at Ace of Diamonds Mine.
The Mira Collection
The Mira Collection by Michelle Pajak-Reynolds features Herkimer diamond quartz crystals mined during the adventure described in the blog post above. Click here to learn more about the making of this collection.
