What is a Herkimer Diamond?

Herkimer Diamonds are exquisite gemstones, cut and faceted by Mother Nature with 18 facets and two termination points.  Although widely referred to as diamonds (it’s easy to see why), Herkimer Diamonds are actually quartz crystals, not diamonds.  They are most commonly short and stubby (less than one inch long) and have a hardness of 7.5 on the MOH scale of hardness, with 10 being the hardest (natural diamonds).  This means they are ideal for daily wear and hold up well in special occasion jewelry, like engagement and wedding rings.  These gems are usually exceptionally clear and exhibit a brilliant sparkle but might also be smoky or contain rainbow inclusions, air bubbles, or black carbon deposits.

The formation of “Herkimer Diamonds” began in the Herkimer County area of New York State nearly 500 million years ago when the limy sediments that accumulated in the salty waters of an ancient sea were gradually compacted under the weight of thousands of feet of seawater, sediment, and rock.  Sea water seeped through the pores of the stone called vugs.  Millions of years later, water rich with silica filled the spaces and eventually drained away, leaving behind silica deposits.  Over time, precipitation, heat, and pressure cycles eventually formed the beautiful double-terminated quartz crystals we call Herkimer Diamonds.  Unlike natural diamonds, Herkimer Diamonds are mined above ground, making them more ethically sourced and sustainable.

Herkimer County is one of the few places in the world where these crystals are easily found, and only crystals mined in this area can rightfully be called “Herkimers.”

 

Demand and Uses for Herkimer Diamonds

These magnificent gems have long been prized worldwide for their use in jewelry and have been featured for sale on QVC in the United States and Japan.  In October 2018, they were made even more famous when Meghan Markle, Duchess of Sussex, wore Herkimer Diamond jewelry at the wedding of Prince Harry’s cousin, Princes Eugenie.  During the Season 16 premiere of “Keeping up with the Kardashians,” Kanye West gave Kim Kardashian a Herkimer Diamond to boost good feelings.

In addition to their use as jewelry, Herkimer Diamonds are also known for being metaphysically beneficial as conduits of spirituality, memory, love, energy, and healing.  It’s believed they have the power to relieve pain, have a purifying effect, and have the ability to stimulate the immune system.  Dubbed “dream rocks,” some claim that sleeping with one in your pillow will enhance your dreams.

Herkimer Diamonds are also coveted by gemstone lovers and mineral collectors searching for unique specimens to study and display.  Did you know The Smithsonian National Museum of Natural History displays a fully reconstructed Herkimer Diamond pocket?

 

Which Types of Herkimer Diamonds Are Most Valuable?

Many collectors are interested in these rare types of Herkimer Diamonds, making them more valuable than other types:

Anthraxolite Inclusions: These are solid black inclusions that are decayed plant matter.

Twins:  When two Herkimer Diamonds are attached and are similar in size, they are called twins.

Smoky Herkimers:  A smoky crystal is characterized by a brownish or grayish color.  This occurs when Anthraxolite is evenly distributed throughout the diamond.

Clusters:  These are groups of three or more Herkimer Diamonds that have formed together.  They make stunning display pieces.

Enhydros:  Herkimer Diamonds with water inclusions are some of the most sought-after by collectors.  The value of an enhydro is dependent on the size of the inclusion and the visibility of the movement of the water floater within the Herkimer Diamond.  It’s fascinating to think the water contained in the Herkimer Diamond is half a billion years old!  Enhydros can be worth as much as five times the cost of a Herkimer Diamond without a water inclusion.

Phantoms:  A phantom crystal contains a small (sometimes microscopic) crystal that fully forms within the host Herkimer Diamond.  These are extremely rare!

Note:  Raw and uncut Herkimer Diamonds still attached to their host dolomite stone are often more valuable than those separated from the host stone.

 

How Are Herkimer Diamonds Graded?

Grading is essential in determining a Herkimer Diamond’s appraisal value.  These are the commonly used grades:

Grade AA

Crystals in this group are exceptionally clear and flawless to the naked eye from all angles.  They lack visible inclusions and have great refractivity.  They are scarce and tough to find, especially in larger sizes.  The most typical use is for collection and high-end jewelry.

Grade A

These crystals might have minor attachment marks, inclusions, or fractures which do not take away from the overall clarity.  These flaws should be at most five percent of the total diamond.  Both termination points should be intact.  The most typical use is in a variety of jewelry products.

Grade B

Crystals in this group should display the general shape of a Herkimer Diamond.  They might be cloudy from internal fractures, have significant attachment marks, or damaged termination points.  The most typical use is loose resale, souvenirs, gifts, and in jewelry as capped pendants or earrings.

Grades C/D

Herkimer Diamonds in the C category will be more than 40% flawed.  The Herkimer Diamond will be more than 60% flawed in the D category and might lack recognizability.  Crystals in this group exhibit extreme cloudiness, missing termination points, and significant fractured sections.  Jewelers can use Herkimer Diamond in these grades as a cutting tool.

 

What is a Herkimer Diamond Worth?

The second determining factor in appraising the value of a Herkimer Diamond is size.  After assigning a grade, measure your Herkimer Diamond and check out what it’s worth:

Size 1/8-inch:    AA – $10, A – $7, B – $4, C&D – $2

Size 1/4-inch:    AA – $15, A – $10, B – $6, C&D – $5

Size 5/16-inch:   AA – $20, A – $15, B – $10, C&D – $6

Size 3/8-inch:    AA – $25, A – $20, B – $15, C&D – $8

Size 7/16-inch:   AA – $35, A – $30, B – $20, C&D – $10

Size 1/2-inch:    AA – $50, A – $40, B – $30, C&D – $12

Size 5/8-inch:    AA – $75, A – $60, B – $40, C&D – $15

Size 3/4-inch:    AA – $98, A – $90, B – $55, C&D – $25

Size 7/8-inch:    AA – $150, A – $130, B – $90, C&D – $35

Size 1-inch:        AA – $200, A – $180, B – $120, C&D – $50

 

Getting to the Mines

Some of the best places to find Herkimer Diamonds are along New York State Routes 28 and 29.  Since all land in New York either belongs to the government (collecting minerals from government land is illegal) or is private property, we recommend three sites open to the public from April through October annually.

The World-Famous Herkimer Diamond Mines

The Herkimer Diamond Mines is an 8-minute drive from Grand Colonial Bed and Breakfast.  To get there, exit the Grand Colonial Bed and Breakfast driveway and turn left onto West German Street (toward Main Street).  Drive to the end of German Street and turn left at the traffic light onto Middleville Road/Southern Adirondack Trail/NY-28.  Continue straight on NY-28 for about 6.7 miles.  Herkimer Diamond Mines is on the left side of the road.

Ace of Diamonds Mine and Campground

Ace of Diamonds Mine is an 8-minute drive from Grand Colonial Bed and Breakfast.  It’s located just past the Herkimer Diamond Mines.  To get there, exit the Grand Colonial Bed and Breakfast driveway and turn left onto West German Street (toward Main Street).  Drive to the end of German Street and turn left at the traffic light onto Middleville Road/Southern Adirondack Trail/NY-28.  Continue straight on NY-28 for about 7 miles.  Ace of Diamonds Mine is on the left side of the road.

Crystal Grove Diamond Mine

Crystal Grove Diamond Mine is a 30-minute drive from Grand Colonial Bed and Breakfast.  It’s located in St. Johnsville, NY.  To get there, exit the Grand Colonial Bed and Breakfast driveway and turn left onto West German Street (toward Main Street).  Turn right onto Main Street, then left on State Street (NY-5).  Continue on NY-5 for 17 miles.  Turn left onto N Division Street, then right onto Lasserville Road.  In 3.6 miles, arrive at Crystal Grove Diamond Mine.

 

How to Find Herkimer Diamonds

“Scavenger Prospecting” is the easiest and safest way to find Herkimer Diamonds (especially for kids).  You’ll be amazed at how many Herkimer Diamonds you can find just by looking around the piles of surface rocks until something sparkly catches your eye or by searching the ground for loose crystals (they tend to be small but high quality).  If you bring a small gardening shovel, you might also have luck finding loose crystals on or just beneath the surface of any exposed soil.

You might also try your luck using the “Find and Break” method (this is where your supplied hammer comes in handy).  The key to finding crystals within exposed Dolostone is to select more porous rocks to break open.  The more porous the rock, the more likely you will find a Herkimer Diamond in a crack or crevice once you break it open.  You might choose to collect and leave intact whole rock specimens with visible crystals or save them later when you have access to more precise extraction tools.

 

Where to Stay – The Best Hotel Near The Herkimer Diamond Mines

If you’re planning to visit Central New York State to mine Herkimer Diamonds, we invite you to experience the charm of a boutique hotel with the convenience of a homestay when you spend the night with us at Grand Colonial Bed and Breakfast.  We’re located at 112 West German Street in Herkimer, New York, just minutes from the three central area Herkimer Diamond mines.

If you’re seeking a truly one-of-a-kind getaway, there is no better way to experience the thrill of mining Herkimer Diamonds than with a comfortable night’s rest and the best-in-town homemade breakfast specially prepared for you each morning.  Immerse yourself in the historic charm of our 1800s Colonial-style house featuring four en suite guest rooms with modern amenities, free Wi-Fi and parking, comfortable bedding, and a private bathroom.

Book your stay directly at grand-colonial.com or by phone at (315) 982-5004.  Cancellation is free for all direct booking reservations.  Pay when you stay – no pre-payment is required.  We offer a return guest discount.  Children are welcome.  We’re dog friendly!  Bicycle rentals are available.

We offer loose genuine Herkimer Diamonds and Herkimer Diamond jewelry for sale at GC Mercantile, our gift shop at Grand Colonial Bed and Breakfast.

 

How to Get Free Admission to The Herkimer Diamond Mines

Grand Colonial Bed and Breakfast will reimburse one adult admission to The Herkimer Diamond Mines each time you book direct and stay with us during the promotional period.  We require a receipt as proof of purchase.  This promotion is valid while actively published on our Deals Page.