Category Archives: Garnets

The Rare Gem Series: Demantoid Garnet

Demantoid?  That’s kind of a satanic sounding name.  The guy who named that stone must have been color blind because they’re green, not red.  Oh well, the Russians named it and used the Dutch word for diamond, “demant”, and the Greek word for alike, “eidos” and mated them together to get “demantoid”.  Discovered on the banks of the Bobrovka river in the central Western Ural Mountains in 1868 the stone quickly became popular among Russia’s elite due to its high indices of refraction and superior color dispersion to that of even diamonds.

Jeffrey Mine Specimen
A rich specimen of demantoid in wollastonite from the Jeffrey Asbestos Mine in Quebec, Canada (minfind.com)

Demantoids are the green version of andradite garnets, a calcium and iron rich silicate mineral.  Garnets are defined in a weird way; they are called “solid solutions”, meaning that the stones will always have a the structure of (SiO4)3 contained with in it, but will be bundled with a different series of atoms to form the particular molecule of the different garnets.  In the case of Demantoids, the molecule looks like this: Ca3Fe2(siO4)3.  I know it is a bit technical, but bear with me.

The Urals are a mountain range born of collision.  They form the seam where the continents of Europe and Asia bonded and made the super continent of Eurasia.  When two continents collide everything gets all orogenous.  As the two massive hunks of Earth merge they have two options: 1) if they are of different densities the denser of the two will subduct (like what happens off the coast of Washington and Oregon between the dense Juan de Fuca Plate and the lighter North American Plate; or 2) if the are the same density (like two chunks of continent) they collide and start to push up as they attempt to override the other equally-matched mass of rock.  We can see this happening today in the Himalayas where the Indian Sub Continent has slammed into South Asia.

The big collision that formed the Urals was about 250-300 million years ago making these mountains among the oldest on the planet.  At one time, when they were a young whipper-snapper, the Urals may have approached 30,000ft in altitude like that of the greenhorn Himalayas.  Time, combined with weather, has reduced the Urals to but a 1,500 mile ridge of hills today ranging from 1,100ft to about 6,000ft at its highest.

When Europe and Asia collided and formed the Urals a lot of rock cooking happened.  When  continents collide and form a mountain range, a bunch of earth is uplifted and piled upon more earth like wrinkles in a bed sheet.  When rocks are buried miles deep they come under great pressure (how long do you think you would last as the bag full of water that is your human form if you had five to twenty miles of rock piled on top of you?), and fantastic temperatures.  Sometimes the temperatures can be in the thousands of degrees!  This heat and pressure metamorphizes rock; essentially there is enough heat and pressure to change the chemical structure of the material, thus creating new minerals in the process.

Metamorphosis is how andradite garnets appear into being.  When the limestones that formed the seafloor between the two colliding continents merged and squished, the added heat and pressure caused mineral leaching.  In Russia, this just happened to occur with some squishing serpentinites (soapstone).  The calcium and iron from these two stones bonded to form the solid solution with the oxygen and silica, that is the basis for all garnets, creating the demantoid.  The special thing about the Russian demantoids is that the serpentinite cased the garnets to form around this stuff called chrysotile which is a form of asbestos.  The thin, long strands of chrysotile make wispy curved inclusions in the stones that look like horsetails.  The demantoids with these inclusions are simply known as horsetail garnets; and they are worth a lot of money.

Microscopic image of a horsetail inclusions in a Russian specimen (Emporia State University, Kansas and the Gemological Institute of America)

From the time demantoids were discovered in 1868, up to the Communist Revolution in 1919, Demantoids were wildly popular.  Even famed jeweler Peter Carl Fabergé (of Fabergé Egg fame) regularly incorporated demantoids into his pieces.  After the revolution jewels were not much of a concern for Soviet population.  Mine production in the Urals started once again in the 1970s when it was realized that outside markets were demanding this extremely rare stone.  Some mining in the Urals carries on today, and rarely some Russian stones can be purchased at auction.

More recent discoveries in Namibia (1996), Madagascar (2009), Italy, Iran, and Afghanistan have come on to the market.  The Jeffrey Mine in Quebec, Canada is producing some of the largest, most beautiful demantoids ever seen.  The Jeffrey is the largest asbestos mine in the world and a big source of contention among Quebecois.

Jeffrey Asbestos Mine Quebec, Canada
The Jeffrey Asbestos Mine is the largest open pit asbestos mine in the Western Hemisphere. It is a fantastic source of mesothelioma and garnets!

Most Demantoids are incredibly small with most gem-quality cut stones being under 1ct.  Stones over 2cts are rare, and stones over 3cts are incredibly rare.  Noosphere Geologic has in its private collection a 5.4ct round-brilliant cut Russian horsetail, as well as a 1.32 oval cut Russian demantoid.  We also have several larger uncut stones in matrix from the Jeffrey Mine, and from Madagascar and Namibia.

The value of demantoids are generally very high.  Eye-clean Russian stones larger than one carat can easily fetch $25,000 to $50,000 per carat, while stones with visible inclusions will get between $1,000 to $5,000 per carat.  The largest eye-clean Russian demantoid is only 8cts and worth upwards of one million dollars.  The largest single stone ever found was a Russian 252.5ct ugly green blob.

5.4ct Russian demantoid
This is a 5.4ct Russian horsetail demantoid specimen (Noosphere Geologic)

In the United States there are several potential locations in the Southeast, Montana, California, and even my home state of Washington where old asbestos mines exist.  If you are going to look, be careful.  Wear masks if recommended, and if you see the long fibrous strands of serpentine (different that serpentinite or soapstone) get out!

Sometimes You have to Go Home Just So You can Come Back Again!

Saturday was my last full day in the Black Hills.  Jesse and I cleaned some of the cabins at the lodge and then plopped ourselves poolside at the rec center in Spearfish.  I love that freaking pool.  Every community and neighborhood in America should have a rec center like Spearfish’s.  After some unhealthy amounts of sun it was time for some burritos at Barbacoa’s (freaking delicious!) where we happened into Jesse’s cousin Micheala who was grabbing a last bite to eat before she headed to California for camping.  I was glad to have the chance to say goodbye.

Inside Barbacoa’s also just happened to be Micheala’s mother who did not know her daughter was in the parking lot.  Strange coincidences.  Micheala’s mother is hilarious and Jesse and I had a nice lunch chatting with her.

From there we hoped into the grandmamobile and drove out beyond a the cowboy town of Belle Fouche to catch the last day of The Stone House Saloon.  This is a little joint operated by a rancher and his family that is only open one week a year during Rally.  It’s an old, bombed-out homesteader’s stone cabin.  Inside the cabin is pealing and covered in “was heres” graffiti.  Outside there is a BBQ and bar and about 50 giant wood cable spools for tables.  Suspended above the spools is jungle netting like MASH unit might have had during ‘Nam for shade.

Jesse purchased a bloody mary and I got a Sprite and we went about investigating the place.  I immediately noticed an older woman and her energetic little jack russell terrier seated on a log bench, so I moseyed over to pet the dog and strike up a conversation.  She was the wife of a rancher from Montana and always came down for Rally.  The dog was six months old and just stupid with energy, bouncing around like an idiot trying to eat every bug within snapping distance.  Our conversation didn’t make it very far through pleasantries before she wanted to be sure I was one of the “good ones”.

Upon learning that I was a prospector and geologist she was keen to know if I was going to vote the “right way” in November.  I told her delicately that I was confident that I was going to vote the “right way”, but that she and I probably had different views as to what the “right way” was.  Then she started making me a little uncomfortable after a diatribe on the Keystone XL pipeline started getting racist when she began complaining about how all those “other people” were ruining a pure Norwegian population up in the Bakken.  The Bakken is the area where there is thought to be upwards of 400 billion barrels of oil trapped in ultra-tough dolomite in Northwestern North Dakota; thousands of Americans of all races in need of work have been flooding the state in recent years.  I was going to brush away a fly I observed that was having dinner on a scabbed over cut on her forearm, but I decided against it and viewed the little bug as a soldier in the ongoing war against assholes.  Eat and grow fat on the evil racist woman, little fly!

I excused myself from the racist and her little dog just as a thundershower started to move in.  The camo-netting did not hide me from the rain so I investigated the dilapidated stone ruins which still had a roof.  Before I had the chance to go far inside Jesse texted and asked me to meet her at the back of the house.  She was seated with her feet dangling out of the second floor window and wanted me to take a photograph of her.  It’s a good picture.  Then I got to go inside.  In Seattle such a ruin as this would smell damp with pee.  In the dry clime of South Dakota we could only, and barely, detect the slightest aged pee.  One one of the tagged walls I found a tag that was circled on the slope of the ceiling of an upstairs bedroom that read, “Jim and Maryanne, Sturgis 1998”.  Inside the circle was every year since (except 2009) written in different ink.  That is a cute way to mark a tradition.  I like that.  The missing year got me thinking and I imagined what may have happened in 2009 that resulted in missing rally.  Financial hardship, a death in the family, their daughter’s wedding, or perhaps a car accident…  They had been so consistent before and since 2009 that whatever it was to cause them to miss that one year must have been really life changing and important for them to miss their tradition.

The thunder and lightning stared getting scary-close so Jesse and I left the stone house for her car before we all were zapped for being in the only thing taller than the grass for a mile in any direction.  We drove back to Belle Fouche and stopped at the thrift store.

Last year we perused the isles of the store and I found that someone had donated the largest collection of kitsch asftershaves I had ever seen.  There were bottles shaped like colt .45s, sports cars, cats, stage coaches, hot rods, cattle, Odie, and more.  Almost all of them had their original box and almost all of them were from the 1970s.  On the boxes would read something like, “Custom vans have become very popular in recent years. Acme Brand would like to celebrate this uniquely American sub-culture with this limited edition bottle of our exclusive Bedroom Eyes Aftershave.”  There is another thing all of these glorious bottles of aftershave had in common:  they all smelled like mustachio’d pornstar in a rainstorm; butterfly collar, polyester, lube and all.  The first place I laser beamed to when we entered the thrift shop was the aftershave isle.  All my old friends were still there waiting for someone with awful taste to purchase and take them all to a wonderful new home with the appropriate amount of wood veneer paneling and faded shag carpet.

Another thing to note about the Belle Fouche thrift store is that I have never seen so many wedding dresses in a second hand store in all my years.  For something that at one time represented and consumed the thoughts of so many little girls for the majority of their lives, and was worn on what was probably then, the happiest day of their lives to be discarded and priced for $70 at a used clothing store is tragic.  There were probably a hundred dresses on one rack and another dozen in giant fancy boxes on the shelf above glowing through the cellophane windows pleading, “Pick me! I am better luck the second time around!”

I purchased a couple of fantastic elaborately patterned shirts for my ever-growing collection and we drove back toward Spearfish.  The rain was hammering the car and the wipers could not keep up.  To our West we could see the front of this storm trying desperately to touch down in a tornado, but fortunately for the ranch it was teasing below, the danger never materialized.  The “buh-blams” I said with every lightning strike did not seem to amuse Jesse as much as it does the boys when I do it, but I kept saying it anyway because, most importantly, it amused me even more!

We napped at the lodge for a few hours and drove to Deadwood for dinner at the Social Club above The Saloon 10… again!  I ate a wild boar pasta and was so happy.  The band downstairs played Nickelback for the 10,000th fucking time.

An early night and we went back to the lodge.  Sunday morning I packed the truck and collected all the things the boys left behind.  Judging from the amount of clothes I found Dave must have driven back to California naked.  Jesse and I had a late goodbye breakfast at some oldpeople restaurant by I-90.  The french toast was a definite and hearty bon voyage for me.  I drove away already missing the place and not wanting to wait until next year to have the time of my life again.

I drive all day.  First was West on I-90 to Buffalo, WY, then South on I-25 to Casper, WY.  I then drove through Casper and passed the Albertsons and the Safeway where last year Aren, Erik and I made the grocery checker very concerned when all we purchased was role duct tape, a 24 pack of water, and a box of condoms.  These are the things that should sound warning sirens inside a store when three dirty men purchase them together.  These three items made complete sense to us, but the look on our checker’s face said that he had a dirty imagination.

I then drove South on SR789 through South central Wyoming.  On the furthest edge of Red Rock Desert I passed what must have been hundreds of kimberlite pipes.  Here in one of the most desolate and dry places in North America probably housed billions, if not trillions of dollars in precious diamonds.  I will be returning soon to my new “Diamond Highway”.  In Rawlins I merged onto I-80 and continued West only stopping for gas and mini donettes (or as like to call them “roadnuts”).  I exited the freeway in Point of Rocks, WY and drove North for 20 miles on “9 Mile Road”.  Yeah, that statement hurts my brain too.

I drove past the Jim Bridger Power Plant, a gigantic coal fire plant that is fed directly by one of Wyoming’s vast coal deposits right next door.  On the Southwest side of the power plant is the Jim Bridger Recreation Area.  Rad, you can breathe the sharp sulferous fart smell of coal-fire exhaust, and go fishing in the toxic retention pond at the same time.  Wunderbar!  But “No Overnight Camping!” reads the sign at the entrance.  Don’t worry, bro, I’m not going to spend my night sleeping under the brain-tingling buzz of high-tension powerlines anytime soon.

The sun set just as the power plant came into view and I had a stunning twilight drive to Black Rock at the North end of the Lucite Hills.  The Lucite Hills are named for the rare mineral found in the rocks there, lucite of course!  About 900,000 years ago a very rare volcanic eruption flooded the area in lamproite lava, quite possibly the rarest rock on Earth.  Lamproite is believed to be burped up from somewhere deep in the Earth’s belly and is rich in minerals like peridot, garnets, lucite, wyomingite, and…. Diamonds!  Lamporite has only been found in a few locations on Earth one of which is the Argyle mine in Australia that produces some 45 million carats of diamonds per year and is the only significant source of pink and ultra-rare red diamonds in the world.

I made camp and set up my cot next to my truck about a mile North of Black Rock.  I had a hell of a time getting any solid sleep as the coyotes were making a racket all around me, and every now and then, made their racket a stone’s throw from my bed (literally, I threw stones at them to get them to go away).  I slept in later than I realized and was greeted by a cool overcast sky.  I ate some donuts and drove toward Black Rock.  I passed the remnants of an old ranchers cabin and took some photos.  I find if fascinating that someone built a home out using the nearby rock, lived in this desolate place herding cattle, and never had enough curiosity to look at the shiny flecks in the rock of their home and wonder what all that green stuff was.

I parked the Honey Badger in a drywash and continued on with just the truck as the road was getting hairy.  When I got close to Black Rock I marveled.  From any distance beyond fifty feet or more any geologist would probably think Black Rock is just a weathered basalt mesa, replete with octagonal columns and all.  Black Rock isn’t black though.  It’s covered in lichens that give it a darker appearance but the rock is actually khaki in color.  It is also very light and not dense like basalt that is found in crystallized columns can be.  There are a lot of gas bubbles and strangely suspended minerals; most of which I could not identify.

My target this day were anthills.  Ants, particularly red ants, are nature’s gem miners.  They pull out anything pebbly and pile them outside their homes making the familiar cone of an anthill.  They do this so that the stones act like shingles and rainwater would runoff and not into their elaborate colony.  Fortunately, when red ants live in the soil of eroded, gem-rich rock, the pebbles they use to coat their hills are often valuable gemstones.  I was going to steal their shingles like a meth-head steals copper wire, like I owned it.

The clouds started to clear and it got hot in a hurry.  There were also no cattle for miles and the local biting fly population got to biting me, a lot.  I probably could have gone for the full glory and just destroyed every anthill in my path with a shovel and classifier screens but one hundred thousand pissed off ants kind of gave me the willies.  Instead, I opted to just crouch next to hill and pick the gems off the top and move on.  Out of a dozen or so anthills I managed to gather around 200 carats of peridot, a few red pyrope garnets, and several diamond candidates.  I was no mach for the flies and bailed about noon and drove for Nevada.

The drive was a breeze, and then it was a gale, and then it was a hurricane.  In the salt flats of Utah my truck was being blown all over the road.  Semi trucks were at a crawl for fear of tipping over, and visibility was minimal.  I was in my first salt storm.  Salt was blasting me at near 100mph and I have never had such a hard time staying on a road that goes more than fifty miles straight without one single turn.

When I got into the lee of the mountains surrounding Wendover I could see again.  What I saw was thousands of awesome race cars, hot roads, rat rods, and drag bikes.  It was speed trials week at the Bonneville Salt Flats and anyone worth their salt (yuck, yuck) were there to try and break speed records.  I snapped a couple of photos of a salt encrusted ’80s mustang at a gas station and drove West.  I reached Elko, NV about sundown and got a room at a Motel 6 ($48 a night was too much… I never thought I would think that about a motel room).  I ate dinner at the Golden Nugget Casino where a very nice meth addict repeated her memorized lines to me over and over but at least she got my order right.  I think she introduced herself to me as “Jennifer” on at least four separate occasions.  I asked if I could have a Sprite and she said they only had Sierra Mist and I did my cliche’d mocking shocked-and-disappointed face.  She thought I was seriously hurt that they didn’t have Sprite and kept apologizing to me for the duration of my meal.  Meth will make you retarded, my friends.  Don’t do it.

The next morning I poked along through Elko trying to find my friend Angie’s mom.  Angie told me to stop and say “hello” her only clue to me was that her mother was named Yvonne and she worked at a general store or small grocery on the same side of the street as the Best Western.  Well, she didn’t work at Roy’s Grocery, nor Elko General Merchandise.  Inside Elko General Merchandise I saw a woman that could believably be Angie’s mother, they looked possibly related, and I asked her if her name was Yvonne.  She told me no, “But a a gril named ‘Hannah’ works here, does that help?”  Sigh.

I was chowing on some pancakes at a diner when Angie texted me: “I’m and idiot! She lives in Carlin, oops. It’s 25 miles away.”

To Carlin, where I found Yvonne just finishing her shift at Scott’s Grocery.  She is a lovely woman and I think, at first, thought I was going to serve her with papers when I asked if her name was Yvonne.

West of Carlin I crisscrossed I-80 on the dirt access roads that orbit it and saw a lot of desert and hot, dry hills and mountains.  I had a fun time hauling ass up a dirt road over a 6,000ft pass watching the Honey Badger shake his money maker in my side mirrors.  I also passed a geothermal plant and wondered if it was the one local Bainbridge pariah Gary Tripp lost his shirt on.  I hoped so.  In my opinion convicted felons who talk endlessly about their alien abduction experiences and past lives, and who also lie about being PhDs, just shouldn’t try to be morally superior to everyone else; and it doesn’t make me a bad person to take joy in their financial demise when they have been terrorizing the poor for decades.

I wanted to hug the Humboldt River when I got outside of Battle Mountain so I drove Izzenhood Rd to a dead end… well, to The Izzenhood Ranch where I they would not let me drive the 300ft passed their home to the other rest of the road.  I double back, with four gallons of fuel wasted.  I got onto I-80 and exited again at exit 205.  The road was fine dust, then it was dirt and graded, then the road vanished.  My map said showed a road, I found the Union Pacific Railroad instead.  Every now and and then as I blazed my new trail some frozen ruts in the mud would appear.  It only occurred to me as I was driving through neck-deep grass (something you should never, ever, never do, by the way, as you might burn an entire state down with the hot engine and transmission!  I had to do it because I couldn’t backup the Honey Badger for ten miles.  I am not that skilled) that I was probably smushing the historic 160 year old wagon ruts of The California Trail.  Oops.

After twenty miles of blazing my own trail I found an actual ranch road and made the turn around the north end of the Iron Range along the Humboldt.  I could see the perfectly sculpted remains of the old Union Pacific Railroad and some of the old trestles even.  I turned onto the Midas Highway and drove into Golconda passing several dozen mine buses.  The mines are so far out into the toolies that no one lives near them so the mining companies have giant buses pick up the workers for their four-day-on shifts.

I breezed into Winnemucca by evening and got a room at Super 8 (only slightly better than Motel 6); I needed Internet to write these awesome trip reports you love so much.  That is when I noticed yet another set of magnetic tail lights bit the dust (No really, they dragged in the dust for hours, and bit it).

Wednesday morning I got new tail lights and made a marathon run home.  The minute I crossed the border into the Oregon Outback everything was dead.  For a hundred miles I drove and every single hill side from horizon to horizon was a charred.  By my estimate 1,000sq miles or more had burned.  No one noticed, it didn’t make the news, and no one seemed to care since this is the least populated region in the whole of the continental United States.  Yet another reason all the air in the Western United States was blue with smoke.  I sped through Burns, OR and savored the daylight drive through Divinity Canyon.  I made a stop to pan some gold out of the John Day River and got a taco from the cuties at the Shell station.  I entered Fossil Beds National Monument and was in awe of Picture Canyon.  The diverse terrain of the the Mountains of central Oregon are always overlooked.  This thinly populated region is the most beautiful in the United States.  Period.  Big mountains, badlands, rainbow-colored ash layers, ancient forests, high plains, green pastures, ambling rivers, old west mining towns, cowboys, hill folk, and tons of animals dodging traffic.  Just gorgeous!

I made it to the dry hay fields of Condon, OR as the sun set.  A few miles later on my decent towards the Columbia River I was startled by the sight of the entire horizon blinking like red Christmas lights.  Some clever person made all of the thousands of wind turbines blink on and off in unison.  It’s hilarious.

Night time, it’s dark, I didn’t see anything, I got home at 3am.  The End!

Until next time…