Herkimer Diamond Mines Inc.

Celebrating 53 Years !!

A Natural Phenomenon

Herkimer Diamonds are beautiful double-terminated quartz crystals which are found mainly in Herkimer County, New York. Incredibly, these phenomenal gemstones are believed to be close to five hundred million years old. The crystals are magnificent works of nature found in the rock, appearing to have been precision cut by man and having a diamond-like geometrical shape; thus, the name “Herkimer Diamonds.”

Many collectors believe the Herkimer Diamond should rival a true diamond. Their reasoning for this is a true diamond found in the “rough” is exactly that, a rough appearing glass-like stone. The diamond must be painstakingly cut by man to give it smooth faces and a geometrical shape.

In fact, Herkimer Diamonds are not diamonds. A true diamond is one of the hardest elements known to man, scoring a ten on a one to ten hardness scale. Herkimer Diamonds are harder than all quartz crystals. They fall at about 7.5 on the Mohs hardness scale, giving the real diamond a close race. For comparative purposes, many man-made steels barely score a seven on the hardness scale.

The majority of the Herkimer Diamonds have eighteen faces. Six triangular faces form the termination points on each end of the crystal. These are separated by a group of six square or rectangular faces. This conglomeration often results in a diamond shape. Variance in the plane of a face surface on a Herkimer Diamond has been measured at less than two thousandths of an inch. Even with today’s technology, man has a tough time duplicating the precision nature has performed on the Herkimer Diamond.

Archeological History

Herkimer Diamonds are found in rock which has been dated at about 500 million years old. During the Precambrian period (approximately 1100 million years ago) New York State and most of the eastern section of North American was covered by a shallow sea. The floor of this sea was constantly being covered by sediments from a large land mass to the west. Around this same time period, a right angle compressive force on the earth’s crust caused a large group of mountains to rise above the sea. These mountains now form the Adirondack Mountain Range in Upstate New York.

By late Cambrian time (approximately 500 million years ago), the lower Adirondack plain and foothills of the mountain range were steadily being covered by layers of clean beach sand and carbonates. This continued for approximately 25 million years and into the Early Ordovician geological period. These limey deposits were covered by thousands of feet of sedimentary deposits and compacted to form layers of limestone rock. One of these layers of limestone rock is called “dolomite” (calcium magnesium carbonate). It is in this dolomite rock that Herkimer Diamonds can be found. Interesting to note, it is also in this layer of Early Ordovician rock that the first evidence of marine life can be found.

A series of evolutionary geographical events continued through the “Ice Age” or Pleistocene Epoch (approximately one-half million years ago). During this period, a giant continental ice sheet covered the region. Rushing waters caused by the melting of this glacier began to erode away thousands of feet of sedimentary rock. Eventually, the glacial erosion uncovered the dolomite rock layer in places, making it accessible to man.

One very revealing curiosity found contained within some Herkimer Diamonds are liquid inclusions. Many crystals have liquid trapped inside, but the high clarity of the Herkimer Diamond allows these inclusions to be seen with the naked eye. Study of liquid inclusions in Herkimer Diamonds sheds some light on the conditions which existed during their formation.

Analysis of the liquid inside the inclusion shows that the solution is mostly water and salts. This salt water was trapped inside the diamonds during their growth stage, confirming that seawater was present. Many of these liquid inclusions have bubbles which float about in the liquid. Some of the bubbles are CO²gas, but not all.

In fact, most of the bubbles are water vapor. During the eighteen hundreds, an English geologist, Henry Clifton Sobry, theorized these bubbles could be a result of liquids being trapped at higher temperatures and then cooling. He proved his theory by gradually heating a crystal which held a bubble in a liquid in a liquid inclusion. As the liquid warmed, the bubble slowly disappeared.

Later Dr. F. G. Smith of the University of Toronto, used Sorby’s bubble filling technique to derive at a formation temperature of a Herkimer Diamond. He found that the bubble disappeared at a temperature of 51 C + C (120˚ F to 127˚ F). This means the Herkimer Diamonds were formed at relatively low temperatures. In 1954, Dunn and Fisher used Dr. Smith’s temperatures of formation to calculate that the dolomite rock had approximately 3000 to 3500 feet of sedimentary cover when the crystals formed.

Herkimer Diamonds are also found with solid inclusions. The most common of these is a coal-like substance called “anthraxolite”. Anthraxolite often occurs inside the pockets where Herkimer Diamonds are formed, giving the pockets a solid black appearance. The locality of the anthraxolite both inside and outside of the crystal, suggests it was present before, during, and after the crystals were forming.

The most popular theory on the baffling process of how the crystals formed suggests water right in carbonates seeped through the dolomite rock. This water became trapped in places and slowly ate away the rock, causing small pockets to form. Later, water rich in silica seeped through the rock and became trapped in the pockets. This water evaporated, leaving large deposits of silica which would eventually form the crystals.

There is no truth that this theory holds water (no pun intended).

Another theory which is easier to accept, takes into consideration that marine life in its earliest forms were present during the formation of the dolomite layer. It has been suggested that early sea plant life thrived in shallow waters which covered the region during the Early Ordovician period. Evidence of this can be seen in the dolomite rock at some locations. Fossils of large cabbage-shaped seaweeds known as “Cryptozoon” have been found in the rock.

The Herkimer Diamond Mines has large abundant elliptical-shaped pockets containing hundreds of Herkimer Diamonds. These pockets vary in diameter from one foot to as large as six feet. It has been suggested that perhaps these pockets were a result of Crypto zoon or some other type of plant life being covered by sediments and eventually decomposing, leaving voids in the rock.

The presence of large quantities of anthraxolite in the pockets could also be explained by this theory. It has been proven by laboratory duplication that this coal-like material could be the result of decomposition of plant life.

Now that we have a theory of how the pockets formed, the question arises as to what was the source of the high concentrations of silica. As previously mentioned many theorize that water highly saturated with silica seeped into the pockets and eventually evaporated, leaving the silica deposits to form into quartz crystals. Others have formed a different opinion to what the silica source could have been.

Marine biologists are aware of the existence of a simple-cell structured seal organism known as “Radiolarians”. These micro-sized sea organisms live in colonies and are known to have existed for hundreds of millions of years. They have a unique habit of secreting silica in glass-like geometrical shapes. Like snowflakes from the sky, over four thousand different designs of these ornate silica secretions have been identified.

Perhaps, these or some other early silica secreting marine life were abundant during this Early Ordovician time and they too were trapped under sediments. Their silica secretions may have formed together, resulting in Herkimer Diamonds.

Recently, a major university has been conducting studies on oil slick control. They discovered a marine organism which would disperse an oil slick by feeding on it. Incredibly, the only remains after the oil had been ingested and the “slick-eaters” had left, were thousands of micro sized double-terminated quartz crystals.

One of the most frequent asked questions concerning Herkimer Diamonds is, “Why are the quartz double terminated?” The reason for this is simply a case of affinity. The silica has no attraction to the dolomite rock and avoids attachment to it. The majority of quartz crystals form in rock rich in silica and this usually results in the quartz forming with at least one end of it attached to the host rock.

Details of when the diamonds were first discovered are to say the least, sketchy. No doubt, the Iroquois and Mohawk Indians who first roamed Herkimer County, found diamonds laying loose in the soil. Evidence of the Indians using the crystals for tools and weaponry has been found. Arrowheads carved from the diamonds have been excavated at some Indian burial grounds. It would seem the Indians would have used the diamonds to adorn themselves, but there is no evidence of this. Perhaps, the Indians believed the quartz crystals to be “spirit stones”, as did many of the southern tribes.

Recent History

Perhaps the first published mention of the diamonds was written by a Professor Benjamin Silliman of Yale University in 1819 in the “American Journal of Science.” Credit for being the first to bring the diamonds to the public’s attention has also been given to James Hadley, M.D., a professor of chemistry at the University of the State of New York. An article he wrote on the diamonds was included in the “New York Medical and Physical Journal” in 1823.

In the lower Middleville area near where the Herkimer Diamond Mines is located today, serious prospectors in search of the quartz crystals were blasting the hard dolomite rock earlier than 1879. Perhaps it was when the road cut which is now Route 28 and runs directly in front of the Herkimer Diamond Mines was made, the Herkimer Diamonds were first found in abundance near Middleville. This road has been known to exist since the early eighteen hundreds. It is common knowledge that when the road cut was widened in the early nineteen hundreds, the highway workers found the crystals by the thousands after blasting.

There’s much local lore on how the diamonds were first discovered. The most colorful of these stories claims that two Revolutionary War soldiers happened on some diamonds laying loose in the soil. They thought the quartz crystals were real diamonds and were sure they had struck it rich. Their commanding officer, the famous General Herkimer, got wind of their find. He planned to help finance the war with the diamonds. Unfortunately, their dreams were shattered when a mineralogist examined the gemstones and informed them they were not real diamonds. This story is hearsay in the strictest sense.

Another story surrounds the Middleville discovery. In the mid-eighteen hundreds, a man by the name of Albert Taber owned property adjoining where the Herkimer Diamond Mines is located today. He had a habit of roaming the woods on this property. One day, he was knocked unconscious after slipping and falling on some slippery ice. Before anybody found him, poor old Albert had frozen to death. When the searchers found his body, they checked his pockets and found several Herkimer Diamonds with fresh mud on them. This fueled speculation that Albert was finding diamonds on the property. This story is also not backed up with much evidence, especially when you take into consideration that Hadley’s 1823 article mentions the Middleville find.

For years, the majority of the local people of Herkimer County believed the crystals to be worthless and took them for granted. After plowing, local farmers would often find Herkimer Diamonds in their fields. These diamonds were probably the result of erosion and usually severely weathered. Many area driveways and small roads which were filled with rock from the old quarry n Middleville would glitter with crystals. A few of the locals did appreciate the diamonds and amassed large collections, which in later years sold for a pretty penny.

The Herkimer Diamond Mines was first opened to the public in 1955 for prospecting by a farmer who owned the property. It’s been said, one way he knew the diamonds were on the property was from watching his cows. Occasionally, one would step in a hole within his pasture and almost trip. The hole would usually turn out to be a large pocket full of crystals. The weight of the cow could have broken the top out of a pocket close to the surface.

Various farmers who took title to the land operated the Mines on a very small scale for years. Prospectors would use the honor system, dropping a dollar in a mailbox for their “digging fee.” Later, demand for the diamonds began to increase. More and more prospectors came in search of the crystals. The Mines was sold to a group of investors who were headed by Mr. Van Atty. Mr. Atty and his wife, who assisted him in the operation of the Mines, began to develop it. The Rock Shop and a public campground for the prospectors were built. Unfortunately, Mr. Atty met an untimely death and his wife was forced to sell the Mines. In 1981, Rena and Rudy Scialdo purchased the Mines.

Current Situation

Currently, the Herkimer Diamond Mines is owned and operated by Dr. Renée Scialdo Shevat who continues to advance the international reputation of the diamond as well as promote the resort for visitors.

Today, as many as five hundred people a day from all around the world visit the Herkimer Diamond Mines to prospect. It is not surprising to visit with prospectors from Sweden, Australia, France, California, Canada, Korea, Japan, Germany, Texas and Long Island!

In order to preserve the supply of these precious stones for future generations and avoid over-saturation of the marketplace, some restrictions have been imposed on what tools may be used to prospect for the diamonds. Power tools, such as jackhammers and jacks, are not allowed at most of the mines. There are also restrictions on the weight of sledge hammers which may be used. At the Mines, every prospector is provided with an appropriate hammer with an admission pass.

Since their discovery, Herkimer Diamonds have been popular among rock and mineral collectors. They can be found in collections from all around the world. The crystals also make very elegant jewelry pieces and are highly sought after for this purpose. Many people prefer to adorn themselves with the “real” Herkimer Diamonds, rather than man-made or cut stones.

The Herkimer Diamond Mines Resort today boasts the largest jewelry, rock and gem store in the Northeast. Dr. Shevat is planning to introduce many more designs as well as designers this year. An extensive museum with authentic fossilized dinosaurs has been expanded to include a Herkimer Diamond Hall of Fame, a new Children’s Reading Room and an exhibit of the largest and finest cut Herkimer Diamonds. In addition, the Mines will also offer a new and exciting Fossiling experience fondly referred to as Randy’s Court (named after the authentic dinosaur in the museum). Already a nationally recognized and award winning KOA Kampground with Kabins and Kottages, the KOA will offer new 50 amp service sites for larger motor homes and recreational vehicles. With all sites on the West Canada trout filled creek many waterfront activities and contests will be sponsored throughout the season. An assortment of dining options including the Crystal Chandelier Restaurant, Diamond Café, and Prospectors’ Pavilion have also been enhanced. Dr. Shevat also plans to expand the evolving wholesale business with international markets as well as the research aspects of the crystal.

The Herkimer Diamond Mines salutes its multiple constituencies. Whether the guest is a family, a boy scout or girl scout troop, public school, lapidary artist or metaphysical expert, the Herkimer Diamond Mines is guaranteeing a GEM of an EXPERIENCE! We sincerely extend our gratitude to our friends and colleagues locally, regionally, nationally and internationally.

The Herkimer Diamond has touched the lives of people in almost every country in the world. It is our intent to offer meaningful and world wide celebrations during our 53rd year!!