secrets about mining herkimer diamond quartz crystals
"Herkimer diamonds" is the name given to the doubly terminated quartz crystals found in Herkimer County, New York and surrounding areas. Examples of these crystals are shown in the photos on this page.
Note that these crystals have the typical hexagonal form of quartz; however, instead of having a termination on one end they are doubly terminated. This is a result of the crystals growing with very little or no contact with their host rock.
The host rock of "Herkimer diamonds" is the Cambrian-age, Little Falls Dolostone. The Little Falls Dolostone was deposited about 500 million years ago, and the "Herkimer diamonds" formed in cavities within the dolostone. These cavities are frequently lined with drusy quartz crystals and are often coated with a tarry hydrocarbon.
Although Herkimer County, New York is the location for which these crystals are named, similar doubly terminated quartz crystals have been found in many other locations, including Arizona, Afghanistan, Norway, Ukraine, and China. They have the same appearance but cannot rightfully be called "Herkimers." The doubly terminated quartz crystals shown in the accompanying photo are from a deposit in Afghanistan.
You might also hear the names "Little Falls Diamond" or "Middleville Diamond" used in the Herkimer, New York area. These are similar quartz crystals named for communities in Herkimer County near where they were found. The generic name "Herkimer diamonds" is used for specimens from all of these localities.
The "Herkimer diamonds" of New York are not a recent discovery. The Mohawk people and early settlers knew about the crystals. They found them in stream sediments and plowed fields. They were amazed with the crystals and immediately held them in high esteem. People used the crystals as amulets, used them to make tools, and traded them with other tribes. However, people began to lose interest in the crystals when European glass beads began to arrive in the early 1600s. 
"Herkimer diamonds" share most of the physical properties of other forms of quartz. They are almost always transparent and range from colorless to smoky in color. "Herkimer diamonds" are, by definition, doubly terminated; however, they are known to occur in a wide range of crystal forms (see illustration).
The crystals contain a wide range of inclusions. Particles of solid hydrocarbon materials are the most common inclusion. They range from small eye-visible particles down to micron-size particles, which, when abundant, can impart a smoky color to the crystals. Salt water and liquid petroleum are the most common liquid inclusions. Carbon dioxide is the most common gaseous inclusion. Calcite, dolomite, pyrite, sphalerite, and quartz (often in the form of tiny "Herkimer diamonds") are common mineral inclusions. 
Some of the best places to find "Herkimer diamonds" today are located along New York State Routes 28 and 29 near Middleville, New York. (When visiting this area it is important to remember that all land in New York either belongs to the government or is private property. Collecting minerals from government lands is illegal in New York, and collecting on private property always requires permission in advance. Learn more about the laws governing mineral collecting in the United States.)
There are several commercial mines on New York State Routes 28 and 29. These include Ace of Diamonds Mine, Herkimer Diamond Mines, and Crystal Grove Diamond Mine and Campground. These mines allow collectors to enter and prospect for a nominal fee. They also rent equipment such as rock hammers, wedges, and other small tools. They also have small exhibit areas where you can view and/or purchase specimens.
The key to finding "Herkimer diamonds" is a knowledge that they occur in cavities (vugs) within the Little Falls Dolostone (see photo above). These cavities can be smaller than a pea or several feet
across. At both of the mines listed above, the Little Falls Dolostone is exposed at the surface, and a significant amount of broken rock is scattered across the quarry floor.
The easy way to prospect is to find pieces of vuggy rock and break them open with a heavy hammer. Usually any vugs found will be empty, but if you are lucky, the rock will break to reveal one or several "Herkimer diamonds" within a cavity. If your visit to the mine will last just a few hours or even a single day, this is a good way to spend your time.
Dolostone is a very tough rock, so expect to work hard. At locations where "Herkimer diamonds" are found, the dolostone is usually heavily silicified. This significantly increases the hardness and toughness of the rock. The use of safety glasses is required, and a pair of goggles is even better. Wise collectors wear gloves to protect their hands. We always wear jeans or heavy long pants and a long-sleeve shirt for "find and break" prospecting. Small pieces of dolostone will sometimes fly when a rock breaks, and they can easily cut or bruise a person wearing short pants.
The "find and break" prospecting method described above is employed by many people who visit these mines and can lead to a few good finds. The keys to success are selection of good rocks to break and not being discouraged if you break fifty rocks without finding a crystal. Here's a tip: The best rocks to break are rocks with visible vugs on the outside. There might be more vugs inside.
Some visitors to the mines have been successful by simply searching the rock rubble for exposed crystals or searching the quarry floor for loose crystals. We found several really nice crystals this way and lots of tiny ones. We have also seen children find many nice crystals this way. This is the safest prospecting method, especially for kids.
For finding large quantities of crystals, the most successful mining method is to break into large cavities in the quarry walls and floors using sledge hammers and wedges (power equipment is not permitted at the mines listed in this article). This method requires tools, patience, time, and a knowledge of how to break an extremely durable dolostone.
On a recent visit to the Ace of Diamonds Mine at Middleville, New York, we met Bill McIlquham of Peterborough, Ontario. Bill was mining for Herkimers with his wife Anne, their friend Laurie Mullett and mascot Duffy the Rockhound. They had located a large cavity and were carefully opening it. (Photos of their work shown here were kindly shared with Geology.com by Bill and fellow miners Cheryl Haberman and Alan Summer.)
The McIlquhams have been mining for Herkimers for about 12 years and have found many large cavities. A key element in their success is a nice array of hammers, wedges, and pry-bars. Instead of bashing the dolostone repeatedly with a hammer to break it into tiny pieces, Bill uses a sledge hammer and wedges to very carefully exploit existing fractures in the rock.
He begins by placing one wedge in a fracture and tapping it an inch or two deep. A second wedge is tapped into the fracture and additional wedges are used if needed. These wedges exert forces that penetrate into the rock and break large blocks of dolostone free. Fractures within the large dolostone blocks are then located and exploited until the large block has been reduced to smaller pieces that can be lifted from the quarry.
If a collector is lucky and determined to prevail over the durable dolostone, the reward could be breaking into a cavity. These cavities can contain a few to a few thousand nice "Herkimer diamonds" that range in size from a couple of millimeters to over twenty centimeters in size. Perfect single crystals, doubles and crystal clusters might all be found in a single cavity.
The cavity shown in the photos was opened by Anne and Bill. It contained over one hundred quartz crystals in a variety of sizes, ranging from a few millimeters to several centimeters in length. A very nice prize for a day's work! Two large clusters from the cavity are shown on this page.
The name "Herkimer diamond" is a misnomer. A misnomer is a name that is intentionally or inadvertently incorrect. It is incorrect because the crystals called "Herkimer diamonds" are quartz crystals rather than diamond crystals.
The name "Herkimer diamonds" has been used for over 100 years and is deeply ingrained in the language of local people as well as the rock and mineral community. The word "diamond" grabs attention and may imply a higher value to the person who hears it than the word "quartz." As a result, some people might be misled or confused by the name "Herkimer diamond." For that reason, anyone who is selling "Herkimer diamonds" must be sure to let all buyers know that they are purchasing quartz and not a real diamond.
Why is this important? In 2015, the Federal Trade Commission announced that the improper use of a mineral species or variety name could result in legal actions against the seller. Their proposed revisions to the Guides for the Jewelry, Precious Metals, and Pewter Industries held up "yellow emerald" (a variety of the mineral beryl known as heliodor) and "green amethyst" (amethyst that has been heated to convert it to a green color) as examples. The name "Herkimer diamond" will likely fall into the category of names that the FTC is working to discourage.
Although the name "Herkimer diamond" is a misnomer, and likely confuses a few people, the name also grabs attention and stimulates curiosity. If these crystals were named "Herkimer quartz", they would probably not be nearly as popular, and far fewer people would know of and enjoy them. Without a doubt, they attract a lot of tourist money to Herkimer County every year.
The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Inexpensive mineral collections are available in the Geology.com Store.
Why hunt for "Herkimer diamonds"? It's great fun and every time you break open a rock you will look with anticipation to see if you liberated an unseen quartz crystal. Nice "Herkimer diamonds" are highly prized mineral specimens and are sought by mineral collectors worldwide. Large numbers of Herkimer crystals are also used in jewelry because their natural "facets" are both beautiful and interesting. Some people also seek "Herkimer diamonds" because they are thought to have "holistic qualities."
If you like minerals and have an opportunity to visit the Herkimer County area of New York, consider spending a day looking for "Herkimer diamonds". Be sure to wear clothes that are suitable for working outdoors. Safety glasses are required, and you will be sorry if you don't wear gloves. If you need a sledge hammer or other tools, you can rent them at the mine for a very small fee. If you want to obtain some nice "Herkimer diamonds" but are unable to visit Herkimer to mine them yourself, please visit Bill's site at HerkimerDiamonds.ca.
ron coleman quartz crystal mining
ron coleman mining
Ron Coleman Mining has been the premiere destination for hands-on quartz crystal mining and precious gem gifts for 30 years. Families and visitors come from all over the country to see our mine inJessieville, Arkansas, and to dig their own treasures.
There are few activities more fun than mining your own quartz crystals. At Ron Coleman Mining, we have a side-by-side zip-line that soars over the crystal mine at nearly 1/4 a mile long; extensive premises boasting a huge mine, RV resort and a large digging area for the intrepid visitor.Our mine is so fruitful that we are certainyou will find your digging fees worth of beautiful quality quartz crystals. It is one reason we are considered one of the best crystal mines in Arkansas.
When you arrive, be sure to purchase and schedule your tour. We offer 6 tours each day. The tour includes a short video of the mine history, guided tour through our Gallery of museum quality mineral specimens, ride on our military vehicle through the public digging area, to the commercial mine and the area we clean, sort and store crystals unearthedby our commercial miners.
prospecting for quartz in new york state - ellenville quartz mine and beyond - where to find rocks
Prospecting for Quartz in New York
By Jeremy Zolan
New York is a state with an abundance of quartz localities. These locations produce crystals of a huge
array of styles from many diverse geologies. While most famous for beautiful Herkimer diamonds from
the Mohawk river valley, there are many other kinds of deposits found within the woods of New York.
This brief guide will highlight some things to look for when out in the field and what tools may be
useful. There is a lot in NY state that may be overlooked!
Most of the quartz deposits in NY differ considerably from the deposits in the Herkimer area, which are
the most well known. While the Herkimer Diamond deposits focus on a sea of isolated pockets that occupy layers in the host dolostone,
most of the other localities in New York work vein deposits. These veins often appear as white quartz
that shoots through the rock, twisting and turning in various lengths, rather different than the deposits the Herkimer Quartz is found.
Often there is a higher probability of finding crystals where you see these
veins intersecting because more space is available for growth at the meeting point. It is important to
take note of the geology in the area where you are to search. Often if you see faulting or contacting,
there can be movement of fluid that can produce crystals. As for contacting, notice that the richest
quartz deposits often form where two different rock types touch, for example sedimentary and igneous
or sedimentary and metamorphic. There is chemical exchange between the rocks which promotes
crystal growth. Getting familiar with some basic geology really does help. Here is a photo below of a
textbook example of a contact in NY of sedimetary rock with the metamorphic basement. If you see
veins originating at this junction of rock, there is a higher chance they will have interesting minerals or
Lets say you have found an interesting vein and are looking to assess it and its potential for specimens.
If you see a hole in the rock, it is in your best interest just to take a look.
It is important to look for pockets containing crystals, or loose material that may have fallen out of a pocket into the talus below.
If you see any mud coming from the veins, especially if it is a reddish or orange color, check it out it as that may
contain crystals! Sometimes pockets can be just filled with dirt or totally clean too.
There is a bit of a list of what tools you will need to prospect and dig quartz in NY. Preparation is
critical. Keep in mind that you will often be looking in rural areas where there will be little or no
service, and having a GPS is often essential. I personally use a Garmin GPSMap 64st which is great,
but if you wish to have birdseye satellite imagery available to you, the Garmin GPSMap 66 series will
make all your wildest GPS dreams come true.
As for the tools you need, I notice that I pack very differently when I am going to prospect versus when
I am going to dig somewhere I already know about. Talking to my good NY prospector friend Dustin
Bartlett (@themodernnaturalist on instagram) we have made some lists of supplies you can buy easily
to get started.
The goal of the prospecting pack is mobility and sample collection. Use a small backpack you don't
mind getting dirty for this. Remember to pack ample water and supplies as you may be in the woods for
hours looking. The focus of your tooling should be light and versatile. Choose tools that are good for a
variety of environments. Here are the tools I would choose for this-
Available on Amazon:
Estwing B3-3LB Crack Hammer 3-Pound
Stanley 16-332 FatMax Cold Chisel with Bi-Material Hand Guard
Stanley FMHT16556 FATMAX Flat Utility Chisel, 1-1/4"
Estwing Gad Pry Bar 18" Forged Geological Tool with Pointed Tip & Chisel End GP-18
Estwing Handy Bar Nail Puller 15" Pry Bar with Wide, Thin Blade & Forged Steel Construction HB-15
Sahara Sailor Survival Shovel, Unbreakable Tactical Shovel-180 Degree Folding Shovel (or similar)
A chopstick for removing crystals from pockets undamaged
Water and Food
Notebook and Camera
I really think these lists should give you what you need to prospect and mine nearly any kind of quartz
deposit in NY other than the Herkimer deposits. You'll find that there will be cases where you might
have to use other tools and leave some of these home. Be creative! You will have to be adaptable and
try different things for different locations. Go out there, get dirty, and hit pockets!
Gorgeous chlorite included quartz Dustin Bartlett (@themodernnaturalist on insta) dug fromhis Lil' Give prospect on the Mass/NY line. Dustin discovered this brand new prospect and mined itusing the techniques and tools discussed above.
Ellenville Quartz Mine, Ellenville, Ulster County, NY
To showcase one of New Yorks MANY quartz locations, we are showing you the Ellenville Quartz deposits. Once mined for iron and copper ore, this location has produced tons and tons of fine quartz crystals that form in quartz fissures.
This old mine has produced many specimens of quartz and pyrite over the years and there is still great
material there to be found. I recommend you park at Berme Road Park and walk to the mine, where the
red pin is. On the back wall you'll find pyrite and quartz crystals. Sometimes you can also find other
minerals like galena and sphalerite.