6 Our Rock Crystal

Little Falls Diamonds

Kathryn Dragan

Loose Herkimer Diamonds on a flat surface
“Little Falls Diamonds” from the collection of the Little Falls Historical Society. Photo courtesy of the Little Falls Historical Society.

“The Little Falls Diamond”

“The hills to the north and south of the “gorge” forming the Mohawk Valley at Little Falls, New York, you might find a small, clear, sparkling stone called the Little falls “diamond”.

This semi-precious stone is not a real diamond which is pure carbon – but is a silicon dioxide (SiO2), or sand and oxygen, the same composition as the glass windowpane although much harder. The Little Falls “diamond” is a member of the great quartz family which include opal, agate, flint, amethyst, and other branches either found massive such as quartz rock from which mountains might be built; or having a definite shape which is designated by the term “crystal”. When the quartz crystal is colorless and clear, it is called a rock crystal. Thus, we identify the Little Falls “diamond” as rock crystal and a member of the great quartz family of minerals.

Our rock crystal is not named after the City of Little Falls but the rock formation in which it was grown by nature. This rock formation was originally a sediment laid down in the Precambrian Little Falls Sea that covered much of central, northern, and eastern New York State, millions and millions of years ago. The original limestone sediment was later altered in composition by a great natural disturbance and is now known as Little Falls Dolomite.

The rock crystal, or Little Falls “diamond”, was fashioned by nature in small pockets or vugs in this dolomitic rock. The crystal is found by breaking open the rock which is often very hard; or it is free in the soil, having been weathered out of the rock matrix. Other minerals associated with and sometimes even included within the rock crystal are: calcite, dolomite, pyrite, and anthraxolite.

The Little Falls “diamond” is to be found in the mineral collections of universities, museums, and private individuals all over the world. It is recognized for an unsurpassed perfection of form and sparkling brilliancy. In fact, the Little Falls “diamond”, or rock crystal, has been mistaken for the real diamond.

Even when found as a six-sided prism capped at each end with a six-sided pyramid forming a crystal with 18 faces, all glass smooth and sharp edged, it is difficult not to imagine such a stone has not, in truth, been artificially cut and polished. When our rock crystal is actually cut into such a “brilliant”, it has a water clearness and lively sparkled that is beautiful even in the terms of gemology.

Let the scientific define it as a rock crystal… we will always recognize it as a Little Falls “diamond.”

By Donal Hurley
Little Falls, N.Y.”

A handful of sparkling gems of varying sizes. Their colors range from clearer than glass to smoky gray, with small pieces of black rock imbedded within them. The light hits them and magnifies the facets of these natural gems. They throw rainbows on every surface, even the darker gray gems refract dulled colors onto the surrounding walls.

They could be diamonds, as they sparkle in the sunlight.

But they are not. Not really, anyway.

That handful of diamonds are nothing more than quartz crystal, found in a very specific part of the world we live in. That part of the world, a little place called Little Falls, sits along the Erie Canal where a series of waterfalls makes it idyllic and, as of 2017, a great place for a movie.[1]

Little Falls Diamonds, or Herkimer Diamonds, are a quartz like crystal that naturally have eighteen facets and two terminating points, making it resemble a video game gemstone just clear instead of bright blue or fiery red. They grow as all gems grow: certain minerals in the drainage through the stone would gather and create beautiful little imperfections that are eventually found by the daring adventurer, or the child with a hammer on a day out with their family.

Life as a Simple Rock

Thousands on thousands of years ago, upstate New York was an ocean.

The Little Falls Sea, as it is affectionately called, covered the majority of upstate New York from Vermont to Lake Ontario. This sea existed during the Precambrian era, one of the many geologic eras that the Earth has lived through. It left behind different types of evidence of its existence . Humanity would never see its glory. This wide expanse of water that covers everything humanity holds dear under its dark waves. But the evidence gives clues as to what might have been there, from fossils to layers of rocks that mark the life cycle of an era. These rocks have been given names and classified by type, color, and hardness. The fossils are named, sent away to museums and displayed behind glass for the world to see. One of the rocks is called dolomite, specifically Little Falls Dolomite due to the sea it grew through. This rock is metamorphic, having transformed from a sedimentary calciferous sandstone into dolomite. Metamorphic rocks are made of whatever was left in their place before. This layer of dolomite tops off at four hundred feet thick. We know this mostly because of geology and geologists. But one special piece of history comes from Donal Hurley.

Donal Hurley, a resident of Little Falls in times gone by, used his knowledge of geology and geography to create a short brief of what the geology of the area was through the ages. This brief is written over four colored pages. Many words are misspelled, the cursive of the pen is difficult to read.


Page from “A Brief Geology on Little Falls N.Y.” By Donal Hurly
Page from “A Brief Geology on Little Falls N.Y.” By Donal Hurly (A transcription of the full document is attached at the end of this chapter). Photo by the author.

Nevertheless, it shows the care that Mr. Hurley had for the environment he studied. Within Little Falls Historical Society there are mentions of Donal Hurley throughout the references to the geology of Little Falls and the prized Little Falls diamonds. He was an active, and well loved, member of many community organizations from the late 1800s until his death in 1980.

Be that what it may, the dolomite is not the special part.

Sure, every child loves rocks, that is a fact. They find them in places where the rocks are formed or, maybe even where their family takes their usual hike on sunny afternoons. I myself was a rock collector as a child and into my later years, embarrassingly enough. But we always looked for the prettiest ones. The ones with an extra swirl of color or an extra sparkle to them.

That is where the diamond comes into play

Is it a “Diamond”?

There is no record of when the Little Falls Silicon Oxide based gem came to the attention of the people who lived in the Mohawk Valley. There is no record of the native tribes of the area, such as the Mohawk, using them, but that does not mean they did not use these rocks for trade or for tools.

By composition and looks, they are not very different from diamonds. They rank a 7.5 out of 10 on the Mohs hardness scale, used to measure the hardness of gemstones. When it comes to the 4C’s of gemstone quality (cut, color, clarity, and carat), they can apply just as they do to a diamond. They can be cut to fit shapes that would please any finely dressed lady, or gentleman. Their color usually stays on the clear and sparkly side, while there can be imperfections such as inclusions or bubbles, or even black carbon deposits. The finest jewelry would be made with the clearest of gems, unless otherwise requested. The only true difference that those with the untrained eye would see is that the sparkle is not the same. A Little Falls diamond, also called a Herkimer diamond because they are found in Herkimer county, NY, is made of something akin to glass, it most little harder and in larger chunks. This means that it will reflect and refract as a pane of glass does when the light hits a window. It is pretty, but the sparkle of a true diamond is something of a different experience entirely[2].

So, is it a diamond?

Not quite. But, for many, it isn’t too far off.

An Industry of Stone

Since around the early 1950s, people have been looking for Little Falls diamonds. People will grab pick axes and hammers and go to town on the local hillsides and creek beds in hope of smashing a dolomite stone open and finding a “vug,” also known as the originating pocket within the dolomite where the “diamonds” form. It has become an industry of its own within the area. There are many campgrounds that focus strictly on the hunting of their stones. Campgrounds have evolved to “miners’ villages” such as the Herkimer Diamond Mines KOA Resort, which is the premier “miners” area for those who wish to spend a week of relaxing, mining, and enjoying the area.

Now, I call them “miners,” but they are not actually miners. A true miner would be delving away underground with a lantern in one hand, a pick ax on their belt, and a caged canary in the other hand. “Mining” these gems is a surface endeavor, involving pick axes and rock hammers at surface level rock formations, making it a great summer time family activity.

The industry of these stones has sprung up since its time as something only locals knew about. In fact, in 1950 a man named Claude H. Smith wrote a booklet on how to best get to the Herkimer Diamonds. “Let’s Hunt For Herkimer Diamonds” describes the geography and geology of the stone as well as what to avoid while searching for them and how to keep yourself, and others, safe while mining. Smith is a bit of a fantastical writer, calling the Mohawk Valley area the “Enchanted Valley,” capturing the attention of the reader whether they be “the confirmed rock-hound or the rankest amateur”[3]. Below is a map outlining the areas where Herkimer Diamonds could be found, marked by the striped section, as well as what features of note or what towns were nearby. This map comes with a caption “After H.P. Cushing, 1901” and comes to Smith from the New York State Museum. H.P. Cushing was a geologist who focused on the Adirondacks and other areas in upstate New York in the early 1900s.


Map from "Let's Hunt For Herkimer Diamonds" by Claude H. Smith
Map from “Let’s Hunt For Herkimer Diamonds” by Claude H. Smith (1950)

An Industry of Falsities

One can see the appeal of a diamond that it is not a diamond. First things first, it is going to cost much less than its true carbon counterpart, and second it has become more of a fun story.

Yes diamonds are pretty, but were they one of the New York showcase pieces in the World’s Fair’s Columbian Exhibition of 1893[4]?

When Governor Roosevelt came to Herkimer County in the early 1900s, did the townspeople not give him a box of the most perfect Little Falls Diamonds?

Does Meghan, the Duchess of Sussex and wife of Prince Harry, not have a whole set of jewelry that is made of Herkimer diamonds?

Okay she also has real diamonds but that is no surprise.

(The duchess does have a collection of Little Falls Diamond jewelry, which includes at least four rings, one set of earrings and a bracelet. Her jewelry designer, Pippa Small, worked with the owner of the Herkimer Diamond Mines KOA Resort to retrieve the diamonds she used. So there’s a little bit of royalty even in our backyard[5].)

Anyway, what are the rest of us supposed to do? None of us can afford a full collection of real diamonds, let’s be honest. But its not always about it being real. Sometimes it’s just about how pretty diamonds are, the real carbon-based ones. People have been faking diamonds for years. Now, with the modern age of science, we can even make real “fakes”.

The market for diamonds at the price of, well, not diamonds, is extraordinary. Buyers are average people who want something sparkly, most of the time.

Occasionally, there are people who want them for more nefarious purposes.

Take, for example, the Great Diamond Hoax of 1872.

This took place in the great, gold mining West, where people were frantic over the silver and gold mines that rested in the Rockies and areas to their south. Two Mexican American War veterans and proud Kentuckians, cousins Phillip Arnold and John Slack, managed to trick many very smart people with a scam. Arnold worked in diamond headed drill bits, so he was able to get his hands on a few uncut diamonds, which he mixed in with a few garnets, rubies and, sapphires. With that bag, he and Slack got to work. With a few well-placed words, a couple name changes, and some well-timed trips to a plowed field of “diamonds”, these cousins managed to dupe many people, including Charles Lewis Tiffany (yes, that Tiffany), General George Brinton McClellan, who was the one time commander of the Army of the Potomac, and Representative Benjamin F. “Beast” Butler (a name he got by being particularly brutal to civilians whilst in New Orleans during the Civil War). These men convinced themselves that $20,000 of uncut gems were worth more than $150,000.

I’m not sure whether the fault is on Arnold and Slack, or on Mr. Tiffany for not noticing industrial grand diamonds as opposed to jewelry grade diamonds.

Either way, the two fraudsters spread their load of false gems into a field where they would lead investors to try to find some gems. These men, not really knowing how gems were grown, would find a few and invest in a heartbeat. It was not until a true geologist, Clarence King, was sent as part of a government survey that the truth was revealed. King knew how rocks worked and was able to prove to the poor duped investors and bankers that they had been lied to. By this time, John Slack had vanished, some think that to a foreign land. Meanwhile, Phillip Arnold got his family a nice house and died of pneumonia whilst recovering from a gunshot wound[6].

In this modern age of science, people are becoming less and less attached to true diamonds due to their origin. Diamonds come from mines and that means a lot of different things. There is a phrase that encompasses what some people think of diamonds (as well as a pretty good movie starring Leonardo DiCaprio[7]).

Blood Diamond.

Much like the phrase “blood money” it means that something terrible happened in order for that diamond to get on some pretty woman’s finger. They are more commonly known as conflict diamonds. In our age of environmental accountability, people are turning to other types of diamonds in order to stop the pilfering of the environment and the people who toil in it. These people have a wide variety of gems to choose from.

White Sapphire: a hard mineral that resembles diamond and is a natural stone. However, it is known to not have the same sparkle as a true diamond.

Zircon: it’s not that hard and it shows wear easily but it is a naturally occurring stone.

White Spinel: Pretty hard, but its true pull is that it can actually come in many different colors.

Moissanite: a real mineral that is artificially produced in lab due to its scarcity.

Cubic Zirconia: a true classic substitute to diamonds. It’s hard and sparkly but it can get scratched and dull over time,

Glass: It’s cheap and clear. Mostly used in children’s jewelry to make them think they have a diamond[8].

Each of these are shown on the “Pick Your Gem!” flowchart:

Flowchart for picking a gem according to one's preferences
“Pick your Gem” flowchart created by the author.

And there are also diamonds made in the lab that are true diamonds. Many jewelry companies speculate if the use of manufactured diamonds should be allowed. But that is mostly due to the monopoly of most diamond mines, the prices that diamonds cost, and the true scarcity of diamonds.

But that is a conspiracy for another time.

Our Rock Crystal

While all of those gems are pretty and good subtitutions for a true diamond, they are still second to our rock Crystal. Truth be told, the Little Falls diamond is unique in all the ways it could be.

It sparkles in the sun and makes beautiful jewelry for those who want to wear it.

They sit nicely on shelves and behind glass for collectors and people who wish to display them for the world to see.

They make for a good day at the park with the kids, as long as you have plenty of water, sunscreen, and energy (which children always seem to have).

The name is known across the world, from the wrist of a duchess to the necks of the women of the Mohawk Valley. There is even a brand of vodka that is poured over layers of Herkimer diamonds, as if that will filter out impurities. (Thanks to Dan Akroyd with their Aurora Crystal Head Vodka[9]).

Even though I am just an outsider, I understand the pride that is found in the Little Falls Diamonds (not Herkimer Diamonds, as I have been corrected by the people of Little Falls). They are things of beauty and childhood memories and history reaching all the way back to the beginnings of known geology.

And I would not know about that geology without the works of one man.

I tip my hat to Donal Hurley, whose words are not only at the beginning of this chapter but also are sprinkled through the geology segment. He taught me the most about where these gems come from and what the land is like. So thank you, Donal. One day I will mine you some Little Falls diamonds and lay a handful at your headstone.

Transcription of “A Brief Geology on Little Falls N.Y.” By Donal Hurly

A – (G)renville- some of the oldest formation in the world. A sediment of very ancient sea of great size. Preceded Cambric period-little evidence now left

B – Syenite – a plutonic igneous intrusive during Cambric period.

(1) plutonic igneous is slowing loosing mass from within the earth and not as volcanic which is from without or above the earth

(2) Intrusive is molten mass thrusting upward and cooling as it nears the surface (extrusive is mass which cools horizontally as between layers of rock formation)

(3) Moss Island. Burnt Rocks, West Shore cut

C – Potsdam sandstone- Pre cambrian sediment

D – Dolomite (Little Falls) known as little falls dolomite rock and designated as Beekmantown by H.P. Cushing but actually the Little Falls dolomite and Beekmantown are two different formations also call calciferous sandstone or sandrock in early reports

(1) Little Falls dolomite is metamorphic (pg 2) rock having undergone a change in chemical composition from original sedimentary formation as laid down in ancient Little falls sea. The word metamorphic means “change”

(2) Little Falls sea was pre-Cambria and covered most of central, west and northern parts of state. This was period of fishes and plants and sediment resulted in limestone

(3) Dolomite is about 400 feet thick at the Rollway (west South side of gorge) at Little Falls and dips to 0 at Diamond Hill, Salisbury

(4) Quartz crystal found in Dolomite.

E – Trenton limestone above dolomite. Laid down as sediment in Trenton Sea – Fossils [Ordovician] Period

F – Utica Shale rest above – Newville Gorge also [Ordovician] period

G – Appalachian revolution or upheaval raised land to expose low, rounded mountains Palezoic Period

Erosion – pemplane – Upheavals

(Pg 3)

H – Drrainage of [Quaternary] Period found rock barrier of Little falls partially due to upthrust. The Mohawk River started east of barrier and Rome river started west- each drainage for their respective flow. Headwaters for Mohawk River was supposed to have been East Canada Creek; headquarters headwaters for Rome River was West Canada Creek. Both Canada Creeks west ancient

I – Little Falls Fault

J – Ice Age of Quaternary Period of 25,000 to 50,000 years ago and lasted from 500,00 to 1,500,000 years. A mile thick sheet of ice covered the area, One tongue of ice advanced down from the St Lawrence; and second tongue of ice came down the Champlain Valley to the Hudson with branch up Hudson to meet the St Lawrence glacier near Little Falls

(1) Ice receded to from Lack Algonquin in the basin of the precent Great Lakes. The St.Lawrence river outlet blocked by glacier. Thus the water drained through the Mohawk valley, forming a lake at Little Falls (pg 4) due to rock barrier which then connected what is now the valley walls. The flow of water was greater and the falls more stupendous by two or three times than the present Nigara Falls

(2) Overflow of ancient lake indicated on south valley wall just west of city where a depression indicates an overflow cut which can be traced to Grant Wrights- Newville – Newville Gorge to valley of Indian Castle.

(3) Shale and dolomite (the softer formations) cut away rather rapidly down to harder igneous syenite. Beach markings on south valley side opposite Country [blub?] indicate lake at those levels for some time.

(4)Pot holes resulted from whirling-grinding action of rounded stones near base of the glacier falls. The difference in elevation of the pot holes indicate a wearing down of the rock barrier. The difference in east to west of the location of pot holes indications a wearing backward of the barrier.

K – Wiabase dike – igneous – black and fine grained – exposed 120 feet wide along the Wolgville Railroad

L – Mohawk Valley of today is composed of an inner and outer calley. The outer valley is from 10 to 30 miles wide. The inner valley is the narrow gorge of Little Falls. This inner valley is the lowest passage East to West from the St. Lawrence to the appalachian range.

The Mohawk River at Little Falls is less than 400 feet above sea level; and only 420 feet above sea level at Rome which is 40 miles west.

  1. The movie “A Quiet Place” was filmed in Little Falls in 2017, (Sorrell-White, 2017: “A Quiet Place” Transforms Little Falls. Utica Observer-Dispatch. https://www.timestelegram.com/news/20171030/a-quiet-place-transforms-little-falls)
  2. Herkimer Diamonds – A Comprehensive Guide to this Little-Known Gemstone. 2018. Jewelry Shopping Guide. https://www.jewelryshoppingguide.com/herkimer-diamonds-guide/
  3. Smith, C. E. (1950) Let’s Hunt Herkimer Diamonds. Geneva, NY.
  4. Podolak, J. (1990) Herkimer’s Rocks Often Yield a Treasure of Bright Crystals. The Buffalo Newshttps://buffalonews.com/1990/05/13/herkimers-rocks-often-yield-a-treasure-of-bright-crystals/
  5. Sorrell-White, S. (2018) Duchess of Sussex wears Herkimer Diamonds. Utica Oberserver-Dispatch. https://www.uticaod.com/news/20181017/duchess-of-sussex-wears-herkimer-diamonds
  6. Wilson, R. (2004) the Great Diamond Hoax of 1872. Smithsonian Magazine. https://www.smithsonianmag.com/history/the-great-diamond-hoax-of-1872-2630188/
  7. “Blood Diamond” from 2006, featuring Leonardo DiCaprio,  Djimon Hounsou, and Jennifer Connelly.
  8. Rosengart, K. (2018) The Different Types of Diamonds. K.Rosengart. https://blog.krosengart.com/types-of-fake-diamonds
  9. This is completely true. Supposedly, three of seven filtration steps for the Crystal Head “Aurora” is poured over upwards of 10,000 Herkimer diamonds (Thomas, A. 2017: This Vodka is Filtered Over 10,000 Diamonds. Vinepair. https://vinepair.com/booze-news/diamond-vodka/)