Revealing a New Facet of the Hope Diamond

Jul 13, 2017
By David Bjorgen - Own work, CC BY-SA 3.0

From disappearing acts to legendary curses, the Hope Diamond has often been found embedded in the center of a good story – often, one shrouded in mystery. For centuries, speculation regarding the unique qualities of this stunning 45.52 carat stone (now in the possession of the Smithsonian National Museum of Natural History's Gem and Minerals department) have abounded – and questions sparked by the recent discovery of the diamond's unusual phosphorescent qualities are no exception.

Jeffery Post, Research Geologist in the Department of Geology Gems, and Minerals at the Smithsonian National Museum of Natural History.

Dr. Jeff Post, curator of the United States National Gem and Mineral Collection, describes the effect of exposure to ultra-violet light on the Hope Diamond as leaving a residual phosphorescence which resembles “a glowing orange coal”. It was this quality which inspired researchers to delve deeper into the examination of this famous stone.

A team of expert scientists and researchers were invited to study the effects of ultra-violet light on several of the rarest stones in the Smithsonian collection – specifically, an assortment of blue-hued diamonds – in order to determine whether this quality was unique to the Hope Diamond, or shared by other specimens. What they discovered was that exposure to the mineral boron (the same element which provides these diamonds with their stunning blue coloring) results in red phosphorescence in all natural blue diamonds.

Not surprisingly, further examination also revealed a new mystery – each stone's pattern of phosphorescence is entirely unique to the individual, resulting in a one-of-a-kind “fingerprint” which may be used to identify each specimen. The reasons behind this phenomenon, of course, remain unclear – but researchers hope that further study of the Hope Diamond may reveal more information.

Until then – it is simply one in a long line of mysteries surrounding this legendary stone.

To read more of The Smithsonian's research into this phenomenon, click here. Or explore information regarding other rare gems and minerals, or view the Arkenstone's current collection of diamonds.


The Adelaide Emails, John Cornish in Australia - 3 of 5

Jun 14, 2017

We're excited to have access to a special series of blog posts coming up written by by John Cornish, Speaker at the 2017 Dallas Mineral Collecting Symposium, while on-site working the Adelaide mine extracting crocoites.

If you missed the first few e-mails in the series, start from the beginning at Part 1.



Good Morning, well, it’s morning here in Zeehan, Tasmania as I write, Tuesday, May 6th to be exact, 8:10 am. Outside it’s pouring, sheet after drenching sheet, wave after wind-blown wave of rain; the house rattles and groans as the wind assaults it while the rain pounds with a million hammer-like blows echoing into the room here where I write. Beside me, the two portable, base-heaters are running at full capacity, doing their best to keep the place habitably warm. Hot water in my mug warms my guts and gives me strength…

Yesterday was a great day at the mine, a day with many triumphs. It started well when a large Tasmanian Kangaroo bounced its way across the Dundas track as I was heading to the mine. These seem to be rarer than the more commonly seen, and smaller, Wallabys. Neat, and then better, later in the day as we were getting wood, Bruce pointed out some Devil scat, right beside our little shed. How cool was that, I’d have loved to have seen an actual wild Tasmanian Devil!

And right next to the building, what a mine photo that would have been!

Once at the mine, after having unlocked and opened the gates coming in, I got the old stove going, a fire quickly helping to cut the early morning chill. Next, a pot of water boiling for some tea would do nicely. By the time Bruc

e arrived, I had things handled and was ready for our newest adventures.

Miner John Cornish in search of crocoite crystals in Australia John Cornish, speaker at the Dallas Mineral Collecting Symposium, next to the mine entrance to the Adelaide in Tasmania, Australia. Photo courtesy of J. Cornish.

We started by loading the big pocket (of which I’d written the other day) from the wheelbarrow into the back of the Subaru. To accomplish this with less effort, I scaled a bit of excess rock from the big pocket, relieving it of some of its unnecessary bulk and weight. When done, we lifted and transferred the pocket to a large plastic rack whose handles would allow us solid purchase as we next lifted again and carried the pocket down the stairs and into the back of the vehicle.

Having it loaded, this was a satisfying accomplishment!

From here, it was back underground.

Several days ago, I’d started working another ceiling pocket. Things were going well and I had about two-thirds of the pocket relieved when things got brutally hard, the rock turning ugly-solid. When the rock changed its character so dramatically, I was forced to abandon my work (for the time being) as the pocket was in a difficult place where the amount of work needed to liberate it was out of sequence timing-wise in the overall “big picture”.

So with no other recourse, wait it did and the days went by…

Orange crystals of the lead mineral crocoite underground in the Adelaide mine, Australia. A shocking cluster of orange crocoite crystals in the Adelaide mine, Tasmania, Australia. Photo courtesy of J. Cornish

Now back at it, it was time to remove the rock that supported the pocket. Yesterday I’d begun this task and truth, it took quite a while to get everything where I wanted, but I did and today, I’ll use a bar to crack the pocket free and with a bit of luck and grace, will drop it safely into Bruce’s waiting hands.

Long story short, we did our job perfectly, concisely, exhilaratingly well and it wasn’t that long after that we were both smiling and posing for pictures with the newest insane treasure we’d recovered for Adam and the Adelaide mine owners group.

Good effort, well done!

From there, with this exquisite obstacle removed, we had the opportunity to examine the precariously hanging, overhead “refrigerator” rock we’d identified days before which had forced us to abandon forward development of the drift to instead develop a raise to identify this hazard’s risk potential.

Work in the raise suggested that the rock appeared to be quite solid and firmly emplaced within the pocket/vein and that after intense back-cutting, essentially hollowing the rock out from behind, removing much of its mass, we’d come to a point where we’ve left supporting walls on whose outer surface an exquisite carpet-like covering of perfect brilliant-orange-colored crocoite crystals awaits.

Before beginning the intense process of collection, we opted for a break and lunch. While eating, a large group of noisy, big, black cockatoos descended on the trees hereabout. Two were within 30 feet of the shed and while I was able to make them out quite clearly through the leafy foliage, I didn’t get the chance to photograph them as moments later, they’d taken wing to another nearby tree. Their raucous cries split the quiet for at least half an hour.

Back at it underground, Bruce took the lead. After we’d checked things out, verifying our safety to both of our satisfactions, he set to collecting two large base-plates covered in glowing orange perfection. He did this in a most unique manner, by using a saw!

Creative methods were used to mine these crocoite crystals in the Adelaide mine, Australia. Sawing rock underground in the Adelaide mine to release crystals of orange crocoite.

Bruce had noted that in some instances, the matrix rather than being pounded or pried, could instead be cut-away using an aggressive and stout, hand-held saw. With this tool in hand, Bruce, like a Master, like the incredibly accomplished collector that he is, cut himself some treasure!

He did this from three different directions, sawing through the rocky/clayey matrix. When these cuts were completed to his satisfaction, he called me in and using a bar, I exploited an opening he’d made to wedge the bar into and then gently, with Bruce below catching, levered the rock down and into his waiting hands.

Together we did this, and with his awesome technique and set-up, the first of two, large, incredible, nearly foot-across crocoite crystal plates were recovered flawlessly.

Smiling until our faces hurt, we hauled our new won treasures out from the pocket-zone and down the drift and into the daylight for the first time. In that half-light of the failing day, the crystals seemed to glow as if on fire.

These are magic days and times…

All told by days end, we hauled out the big pocket and three flats filled to bursting with top-notch, world-class specimens. Unloaded later in Zeehan, it’s safe to say that it’s been a good run getting to this point and still, there are incredible days yet to come!


We'll be updating more of John's adventures in crocoite mining. Love what you read? Join us later this summer for the Dallas Mineral Collecting Symposium to hear John tell his stories in person, or start reading from Part 1 of his e-mail records!


The Adelaide Emails, John Cornish in Australia - 2 of 5

Jun 8, 2017
Collecting crocoite crystals in the Adelaide mine Collecting crystals is no easy feat! Photo courtesy of J. Cornish

We're excited to have access to a special series of blog posts coming up written by by John Cornish, Speaker at the 2017 Dallas Mineral Collecting Symposium, while on-site working the Adelaide mine extracting crocoites.

This is the second part of his e-mail records from his trip. Miss the first post? Catch up here.



Rainy day today. No matter underground of course, but still, the rock has begun to weep in certain areas...

Today was a good day. Not a wonderful over-the-top-day, but a good day none the less. Bruce and I, we've been driving a raise to access an area of the pocket-zone behind a large refrigerator-sized, dangerous, block of hanging-wall rock which seems a real killer. Rather than tempting Fate and driving on beneath it, we choose to pursue this extremely physical option. When our vertical work is done, we'll once again drive towards the pocket-zone, coming in behind this hazard so as to safely neutralize its negative potential.

While driving the raise, I broke into a decent pocket. As it's exposed itself, the opening is about 14 inches wide by maybe 6 inches tall. Within the pocket, a pristine forest of black manganese-oxide coated, multiple generation crocoite awaits. The crystals are very tree-ish, where a dominant individual approx. 2 inches long is the platform from which second generation crystals have grown as myriad outward-flaring, branch-like overgrowths.

Being me, and since the pocket was of a supposed/imagined "manageable size", even though so incredibly difficultly positioned directly overhead, I decided to go for it, to collect the entire pocket complete!

I'm in a world-class mine pursuing world-class minerals, why not collect world-class specimens surpassing everyones wildest expectations when the opportunity presents itself?

This pursuit equals intense... INTENSE fun! Challenging me beyond beyond! Eagerly, hungrily, ehthuiastically, humbly, I set to my task and began carving the rock away from the pocket, bringing it out in high relief as over time, monolithically, it revealed its true massive self.

This work took me several days, but today, 5/2/2014, I successfully separated the pocket complete from Mother Tasmania!

Exhausted and vibrating, at first, my job done, this was "enough" for me. I turned off the hammer and rested in the close claustrophobic confines of the raise, panting from the exertions of driving the hammer into the rock so as to violently, gently, softly, perfectly, drop the pocket down onto the two wooden support "toms" Bruce and I had set specifically for this purpose, to catch the pocket's descending weight, during this magic, hard-sought-and-now-realized-moment.

Success. Hard-won-success! Nice!

Adam had told me, when I'd shared my thoughts regarding the pocket, he'd said, "No worries, the pocket will break apart long before your able to collect it". One word, one... HA!!!

What a kick-butt moment...

Collecting fine minerals like orange crocoite from mines is a difficult feat. Delicate spindly crocoite crystals from the Adelaide mine in Tansania, Australia. Photo courtesy of J. Cornish.

Rest time over, once again, I started up the hammer and used it to scale away the loose rock from the pocket mass and to open the area around the pocket so as to further assist our recovery. With these tasks done, I next set to pounding the drift walls and ceiling, scaling back hundreds and hundreds of pounds of rock so as to allow our passage as we bring our big prize down. By the time I was done, I'd taken exhausted to a whole new level. Sweat cascading, it was time to come out from the underground, to tell Bruce what I'd done...

... After taking a break for lunch, Bruce accompanied me underground for the first time today. I had some ideas regarding how to bring our big prize down (currently it is resting in space, sitting on the "toms"). He thought my vision sound and thus, we began our first steps towards recovery. Bruce, after measuring, cut a length of board to size and wedged it over the lower "tom" and against a recess I'd opened with a big flat surface on the opposite, far-side of the raise. Next, I was too big, Bruce wedged himself into the raise and using a small bar, pried the pocket over and onto its "back", a large manageable surface, on to the board he'd just set. With that accomplished, our next duty was to once again clear away the excess rock from around and on the pocket itself and then, pull/draw the pocket down the board and across the raise to its opposite side.

With a bit of effort, together, we finished this task and then, there we were, it was after 5:00 pm and it was time to call it a day. Tomorrow we'll continue our monumental task of bringing the pocket, all 2 feet and maybe 200 + pounds of it, down from a height about 12 feet above the floor.

Just another day crocoite mining on the west coast of Tassie!

So, what did you do today? Chuckle, Smile!!!

Difficult underground mining conditions make mineral collecting a tough task. Crystals like orange crocoite lie deep underground in pockets. Photo courtesy of J. Cornish.

The Adelaide Emails, John Cornish in Australia - 1 of 5

May 29, 2017
Orange crocoite is extremely delicate and fragile John Cornish in the Adelaide mine. Photo courtesy of J. Cornish.

We're excited to have access to a special series of blog posts coming up written by by John Cornish, Speaker at the 2017 Dallas Mineral Collecting Symposium, while on-site working the Adelaide mine extracting crocoites.



I'm still down here in Tasmania, upside down and in the future. I've been here 3- weeks now (with another 3 to go), this is my 3rd year (!!!) working the Red River [crocoite] pocket for Adam and the boys. When I arrived, we were hot on the chase and collected (honestly) from 10 to 20 flats of specimens a day. Among the many treasures recovered during this time were 2 truly exceptional museum-sized and caliber plates, both about 14 x 20 inches and each coated with lustrous spiky forests of brilliant orange 3- inch crystals. Zero damage, pristine perfection, the mine and I at our best!

The Adelaide mine has exceptional crocoite crystal specimens Spectacular pockets need special care to avoid damage. Photo courtesy of J. Cornish.

Since those fun, glory days, we've left crystal collecting behind. Four or 5 days ago everything turned a corner. The pocket completely changed its character. Where we had a very defined near-vertical feature heavily mineralized with crocoite, much of it in-place (there were several areas where the foot wall had collapsed that we've worked through coming to this point), now the structure is widening and the hanging wall, unable to support itself, is presenting areas of massive collapse. One block, from up high, partially peeled away and hanging, was dropped in a controlled fall several days ago. It'd be easy to estimate that the block weighed well over a thousand pounds. When it fell, it revealed another peeling block approx twice as large behind it and another about half the size above it. Before us, an even larger peeling block, 4 x 6 feet awaits. All are accidents waiting to happen and an immediate redefinition of our activities has resulted.

Currently, we are driving a raise behind the collapsed structures to come in behind them, allowing us the opportunity to remove these dangerous elements as safely as possible.

As ever, my collecting partner Bruce Stark continues to be the penultimate example of competency and insight and together, we are making solid careful progress. As we've driven the raise, like little bonuses, we encountered several black-oxide coated, crocoite crystal pockets in the hard Tasmanian mother-rock. From these, several flats of specimens have been collected. The crystals here are quite typical one pocket to another and are extremely needle-thin and up to two inches in length. Where exposed, as hoped for and expected, they are fiery-orange colored and lustrous. Currently, another of these style pockets is exposed. It is directly overhead and appears to be about three feet long, though its true dimensions are as yet unrealized. I had hoped that we'd be into the main structure by now, but with the black coating before me, always associated with periphery halo pocketing around the main structure, it appears we've a bit further yet to dig. Once this pocket is defined and collected, we'll be back to the dirty business of driving our raise.

Ah, the sweet romance of mining!

We'll be updating more of John's adventures in crocoite mining. Love what you read? Join us later this summer for the Dallas Mineral Collecting Symposium to hear John tell his stories in person, and catch Part 2 of 5 of his e-mails in our next blog entry!


Mine shafts can be dangerous, but those in the pursuit of crystals delight in the thrill of the hunt. Underground shot in the Adelaide mine, Tasmania, Australia. Photo courtesy of J. Cornish.


Won't Be Fooled Again: Big Differences between Gold and Pyrite

May 26, 2017

Pyrite is a compound mineral of iron and sulfur. Yet, to the untrained eye, pyrite looks nearly identical to the chemical element gold. There have been countless stories throughout history of grand explorers being fooled by pyrite – earning it the title of “fools’ gold”.

Peru on quartz from Peru bears strong differences when compared to gold specimens. Peru is famous for the remarkable pyrite crystal formations found there.

One such explorer was Sir Martin Frosbisher, an English Privateer, who was one of the first miners in Canada.[1] He found what he suspected was gold on Kodlunarn Island on his first voyage to the New World and shipped 1,400 tons to Europe. However, when the mineral made it to Dartford to be smelted, they learned that the rocks were made of pyrite.

The colonists at Jamestown were also fooled when they rowed up the Potamac river.[2] The sands of the river were glistening with golden pieces, creating a frenzy for Captain Newport and his crew. Believing they had struck it big, Captain Newport shipped 1,100 tons of the shiny sand to England, where it was later found to be pyrite.

How to Spot the Difference

Gold and pyrite may seem similar because of their appearance, but the reality couldn’t be further from the truth. There are distinct differences between gold and pyrite that are discernable with the human eye. Some of the differences are in their:

  1. Density
  2. Color
  3. Hardness

At first glance, spotting the differences between gold and pyrite can be challenging. With enough practice and a sharp eye, you won’t be fooled with “fool’s gold”.

  1. Difference in Densities

Prospectors knew that gold and pyrite behaved differently in a sifting pan because of their densities. Gold in its purest form has a density of 19.3 grams per-cubic centimeter and will tend settle at the bottom of a sifting pan full of sand.[3] Pyrite is a compound of chemicals with a density of 4.8 grams per-cubic centimeters and will rattle around the pan more loosely than gold.[4]

  1. Difference in Color

While both gold and pyrite both shimmer in the sun, pyrite takes on an exaggerated shininess like polished brass because of its metallic luster. Gold also has a metallic luster, but it retains a solid color in direct light better than pyrite. In ideal conditions, pyrite will form isometric crystals with equal faces. This allows for the mineral to shine better than gold, whose malleable form releases less shines.

  1. Difference in Hardness

The most distinct difference between gold and pyrite is in their hardness. Gold is one of the most malleable and ductile metals on earth. The mineral can take any shape when flattened and is easily scratched with a pocket knife.

Pyrite is noticeably harder with a hardness of 6 on Mohs scale while gold is at a 3. Pyrite is not easily scratched and will shatter like glass if struck by a hammer. In fact, if you take a piece of copper and scratch it with a piece of pyrite, it will a scratch on the copper. If you repeat the test with gold instead of pyrite, the gold will be scratched.

Spotting the differences between gold and pyrite takes practice – but a little know-how will take you a long way. Next time you’re digging for treasure and you’ve found a golden nugget, you’ll be ready with the on-site tools needed to tell the difference.

GOLD Examples


PYRITE Examples


Want to see the difference between gold and pyrite in-person? Follow the Arkenstone on their many mineral shows throughout the year! Information on the shows we’ll be attending can be found on our Mineral Shows page. We’d love to meet with you and talk about the specimens in our collections!

We’ve recently updated our galleries with many impressive specimens from around the world. You can find our latest collections here.

[1] Dana H. “Famous Fools for Fool’s Gold”. Scientific American.

[2] Ibid.

[3] “How heavy is a gold bar?”. Elmhurst College.

[4] “Pyrite”. Mindat.

Chinese Game Show Promoting Minerals

May 21, 2017

By Dr. Robert Lavinsky and Tom Moore

We recently received a link to an hour-long episode of a Chinese game show (in Chinese, of course) in which a panel of minor celebrities and some experts competes to see who has the most knowledge regarding various objects important in Chinese culture. Objects may include antiquities, carvings, ceramics, bronzes, paintings, calligraphy and, especially, jade -- and also what their retail value might be. Sounds like fun, especially in this case, as they were faced with having to price some very fine Chinese mineral specimens!

The popular show is produced by CCTV (the government-run television station seen by all Chinese households. The featured item in question is a large specimen of inesite from Fengjiashan mine in Hubei Province. The host proceeds to engage the guests in a discussion about "rocks," showing them a range of photos of beautiful specimens. At the end he has them gasping in surprise at the high values associated. This seems to be part of a gradual educational effort by the Government, in concert with the museum building initiative reported in the
January-February 2013 China Supplement, available for reading online (free!) here.

Watch the clip online!

Summer Fun for Rockhound Kids!

May 5, 2017

Summer is flying by, but there's still plenty of time to plan mineral activities for kids.

The summer months are prime season for rock and mineral collecting – but that doesn't mean the professionals should get to have all the fun! In fact, there are many rock and mineral collecting camps which focus on encouraging the development of younger rockhounds.

Youngsters who are excited about pursuing their interest in geology and gemology may benefit greatly from attending a summer camp or field expedition geared towards their age group – and may find themselves gaining the foundational skills and knowledge they need to nurture a lifelong hobby or career.

At iRocks, mineral collecting is not just our business – it's our passion! And we strive to fuel the flames of those who seek to take their interest in rock and mineral collecting to a whole new level – no matter their age. That's why we've decided to bring you these tips for finding the right summer learning program for your young rockhound. We hope your whole family benefits!


  • Start locally. Many museums and science centers offer incredible summer camps for youngsters interested in the earth sciences. Local collectors clubs and geology-focused attractions may also be a good bet – so make sure to check out their summer offerings and event schedules!
  • Keep it age-appropriate. There are many types of rock and mineral collecting camps, but the one you choose should depend on the age, independence, and skill level of your youngster. Younger children may be content with an exploratory day program, such as those hosted by your local museum or science center – whereas teens and older youth may be more engaged by a field expedition geared towards their age group.A helpful tip: The online search tools found atKidsCamps or Activity Hero can help you locate independent camps or programs located in your area, and then narrow selections by program type and age group.
  • Search by specialty. Some programs choose a specific focus for their youth programs, such as this Colorado program which focuses on rock and mineral collection in the vicinity of prehistoric evidence and fossils, or GIA's GemKids, which focuses on gemology.If your youngster has a particular interest or area of geology which holds special fascination, try searching for that particular focus or specialty, to see what arises.
  • Get out and about. Consider taking a Geology Adventure , or planning a trip to the closest State Park or National Park for some geology-focused exploration. Contacting your local recreational authority can also be helpful, for those who have interest in a local field expedition.
  • DIY Rock Camp. Unable to find a summer program in your area? Consider hosting a do-it-yourself rock and mineral day camp for your youngster, and a few friends. You can find some simple, kid-appropriate geology experiments and rock and mineral-related projects at com or Science for Kids – or contact your local science center or university to arrange an exploratory field trip, or guided tour of their geological exhibits.

We're confident that with just a little digging, you'll be sure to find an array of programs and adventures designed just for your amateur rock and mineral collector!

Prefer to explore our online collection of gems and minerals? Click here.

How to Build a Great Mineral Collection on a Budget! (Guest Post by Phil Persson)

Apr 24, 2017

By Phil Persson

Mineral collecting is one of the greatest hobbies in the world. I often find that the word ‘hobby’ seems inadequate for what is a lifelong, all-consuming passion for many serious mineral collectors. For as many reasons as there are for collecting minerals, there are ways of acquiring them. Some people are die-hard field collectors and their collections reflect many hundreds of hours swinging hammers and chiseling outcrops, traveling mine-to-mine in search of fine mineral specimens to add to their cabinet. Others attend club meetings, field trips, local rock swaps, and silent auctions where they might spend $10 or perhaps $20 on a modest specimen for their collection. For such collectors, the enjoyment of the hobby may be largely related to the social aspects- the meetings, the club shows; the myriad ways in which we engage and participate with our tight-knit community of fellow rock nuts. For others still, the thrill is in the hunt for a true ‘trophy specimen’ whose value can easily climb into the tens or hundreds of thousands of dollars, and whose acquisition may feel more like an initiation into the secretive and zealous world of high-end mineral trading. Regardless of how and why we collect minerals, with the exception of the field collecting purist, we all want the same thing- to acquire as nice of a specimen for our collections as we can for the least amount of money. For those blessed with the financial means to acquire whatever they desire, the following advice many not be particularly important, but I suspect that most collectors reading this have asked themselves at one point how they can improve their collection and still stay within their budget. I offer here a few bits of advice gleaned from 20+ years of collecting and selling minerals, most of the time on a fairly modest student or self-employed budget.

  • Be mobile. The late Rock Currier, a legend of 20th century mineral dealing and collecting, once remarked that finding good minerals was something akin to the random searches ants will do for food, where they leave the anthill and seemingly wander in circles until something tasty is found. Compared to having lots of disposable income, Rock opined, the ability to do such ‘random searches’ was probably more important in locating and acquiring good mineral specimens. This use to mean that one had to have a lifestyle akin to Rock’s: traveling the world from far-flung recently-overturned dictatorships to musty museums in some forgotten corner of Eastern Europe seeking minerals for sale or trade. In the internet era, however, mobility has taken on a new meaning that is not always physical. We now are connected as collectors more than we have ever been through portals like, the Friends of Minerals Forums, and social media platforms like Facebook (follow The Arkenstone and!) and Twitter. I have acquired many good minerals, particularly from defunct ‘classic’ locales in far-away countries which are difficult to acquire here in the USA, through ‘friends’ on Facebook whom I have connected with via the larger mineral community online. While I know few of these people ‘in person’, we have built relationships online which have enabled advantageous trades or purchases where I was able to get minerals within my budget which I would be unlikely to find at a US show or other venue.Physical mobility in acquiring good minerals on a budget is still important, however. This does not have to mean expensive airfare and uncertain safety in some distant corner of the world- just look at the annual Tucson gem and mineral show. While visiting this event, I have sometimes taken a day trip down to the world-famous locality of Bisbee, Arizona, arguably the most important in Arizona and one of the major mineral locales of the United States. While the mines are shuttered and the town now resembles more an artist community and tourist destination than mineral mecca, good minerals at reasonable prices can still be found for the discerning collector at local rock shops and museums. I have added several very fine Bisbee crystallized native copper specimens to my collection in this manner which would have probably been outside of my budget otherwise.


Freemasons meeting in the Copper Queen Mine, Bisbee, Arizona Ca. 1897. Though many important specimen-producing mines and districts such as this have been closed for many years, they are still world a visit and may occasionally yield great minerals for sale at fair prices. (Photo © Library of Congress) 
  • Be Knowledgeable. This may seem self-evident or at worst patronizing to say, but knowledge truly is power. Nobody, even the most seasoned, well-traveled dealer or Ivy League mineralogy PhD can know everything about minerals, so it’s best to find what really gets you excited and specialize. Perhaps that specialization is regional - after having lived in Colorado for 10+ years I now enjoy collecting and learning about minerals from my adopted state. One could also specialize in one mineral - numerous incredible collections of just quartz, calcite or perhaps tourmaline have been assembled. Chemistry is another great way to build an important specialized collection, whether it be silicates or sulfides. Some people just love all minerals- I confess I am part of this group. For us, knowledge is acquired in bits and pieces, but constantly, and always about something different depending on what we’re been able to buy or collect. Again, the internet age has democratized the education process in new and exciting ways. While an advanced degree in geosciences and a large library of mineral books, journals and other publications might have been the traditional avenue to become a ‘mineral connoisseur’, this same knowledge can now be acquired online if one is patient and committed. I know of a number people within the mineral community whose ‘formal education’ may have stopped after high school but whom possess a breadth and depth of knowledge on minerals which most PhD museum curators would envy. The pursuit of knowledge is not just pedantic either- the more you know about minerals, the more you are likely to recognize a great deal hiding under a mineral dealer or collection heir’s nose, or be able to confidently purchase an unlabeled specimen at a good price which less experienced collectors might shy away from because you know the locality and provenance.
Fine group of golden calcite crystals on sphalerite from the Elmwood Mine, Tennessee USA ~38 cm across, acquired by the author in 2015 while volunteering to help set up a local museum sale- the specimen was part of the sale materials.
  • Be Fair. The mineral community is exactly that- a group of people whose shared interests, passions and obsessions unite them under a common banner. More so than collecting fine art, or stamps, or baseball cards, I would argue, mineral collectors are tight-knit and often nurturing and supportive of each other’s growth as collectors and scientists. As members of a community many in the ‘general public’ would find strange or even pointless, we have developed a certain ‘outsider perspective’ which we combat using the strength of our own community. As such, fairness and honesty are critical in being able to acquire good minerals on a budget. The cynic might argue here that the previous suggestion of ‘recognizing a great deal hidden under a dealer or collection heir’s nose’ requires a certain dishonesty or swindling, but I believe that so long as the collector or dealer operates with integrity, ‘getting a bargain’ does not have to equal ‘ripping someone off.’ Yes, scour the world for former rockshops-turned-garage sales piled with flats in someone’s backyard holding treasures only you can identify. Yes, develop relationships with older or more experienced collectors not only because you can absorb their knowledge but because our time on earth is finite and one day you may be able to acquire those minerals for your own collection. Just do so fairly. The mineral community is surprisingly small for how global it has become, and the flipside to the interconnectedness of our community is that when you lie, steal, or treat people unfairly, your reputation will undoubtedly proceed you. I have been amazed at how when I meet someone in the mineral world and have to mention only the most peripheral details of a certain individual before the person I’m speaking with knows exactly which ‘bad apple’ I’m talking about.
Large group of native copper crystals from the New Cornelia Mine, Ajo, Arizona, 16.5 cm across; acquired by the author from the heirs to a small collection whose gemstone portion a friend had helped appraise.
  • Be Creative. This is perhaps the most difficult piece of advice to give succinctly. For those with lots of money, the flow of ‘good rocks’ usually points towards them anyways, and creativity may revolve more around what to acquire and when versus how. For the rest of us the ‘how’ question is usually central, and revolves around money most of the time. Today, however, between the internet, mineral shows, clubs, museums and events across the world, and our increasingly globalized society, there are many ways to acquire good minerals at modest prices. Cultivating relationships is crucial. Humans interaction is driven primarily by psychology and collecting minerals is no different. Gaining trust and building rapport, while perhaps not resulting in immediate gains to your collection, are important in acquiring good minerals at prices you may not be able to find at a show or online. Browsing venues like eBay, Craigslist, and local garage sale listings may also not yield immediate returns to your collection, but most of us who have been collecting for some years have at least one story of a great “sleeper” specimen or collection acquired in this way. Finally, consider being a dealer yourself. No, I don’t mean quitting your ‘day job’ (though some have ended up doing this in the end) and hustling rocks for your daily bread. I consider a dealer to be anyone who has sold a specimen at some point in their life, which includes most of us.

Buying ‘in bulk’ not only can get you a deal on an individual specimen you want for your collection which might be out of your reach otherwise, it can establish valuable relationships with suppliers and collectors that will pay for themselves many times over in the future. Selling minerals can be a great way to finance your future acquisitions, as well as connect on a new level with the mineral community.  Finally, be creative with how you ‘stretch your dollar.’ Perhaps you really want a good Sweet Home rhodochrosite for your collection and are dismayed to find that even a thumbnail which looks like it took a trip through the rock tumbler will now run you a thousand dollars or more. But, you have a friend who has a friend who has some Colorado minerals for sale. They are only a small part of a once great collection she has which she has sold to various dealers over the years.  You meet at a mineral show and strike up a friendly conversation that leads to a casual friendship. One day, she invites you over to her house and shows you a flat of minerals she has- some pyrites, a calcite or two, some nice thumbnails, and then a very fine Sweet Home rhodochrosite. Bingo! She discloses she wants a fairly large sum of money for the specimen, but after researching the locality extensively, you are now knowledgeable enough to know it is a good deal and one you are unlikely to find again. You take out a small loan from a friend to acquire the lot from her, sell the other specimens, pay back your friend, and the Rhodo is now yours for a modest end-cost. A lot of work, you may say, but to myself and many others this is part of the fun of the mineral world, the ways we build community and find clever and creative ways to add to our never-ending collections.

“De Re Metallica” by Agricola, published in 1556, at the time the leading source of knowledge on minerals and mining. While texts like this are still critical in building a knowledge of minerals, the internet has become just as important. (Photo © Drek Gee/Buffalo News)

In closing, I firmly believe we live in the “Golden Age” of mineral collecting. Never before has the pace of mining and discovery been so synchronized with ease-of-access and the interconnectedness which defines our global mineral community. Yes, prices for fine minerals, particularly at the top of the spectrum, have risen dramatically over recent decades, but this is turn has popularized collecting to a new group of privileged people who in turn support and justify specimen mining operations and specimen recovery from active mines around the world. This may be one facet of life where ‘trickle-down economics’ actually has some effect. One can visit a mineral show in Tucson, Denver or Munich and in an afternoon be transported around the world to what is new (sometimes very new) in the mineral world, and often have the luxury or ‘price comparison’ between dozens of dealers offering specimens from the same find or pocket until you find the specimen that speaks to your aesthetics and your budget. Most of all, stay inspired, stay excited, and know that staying within your budget as a collector does NOT mean staying at the same level of minerals or collecting!


Special thanks to Phil Persson for giving us permission to post this great article! 

Kay Robertson: A Treasure in the Mineral Collecting

Apr 13, 2017

- Memories from Dr. Robert Lavinsky

Kay Robertson collected from the age of 8 for nearly 9 decades. Cases of fine minerals are featured decor in Kay Robertson's home.

I will say that, in a world full of characters and crazy collectors, Kay stands out as one of the most passionate collectors I have had the privilege to know - to this day, at 97, she is as passionate about minerals and the glory of knowledge that comes from them, as she must have been 90 years ago when she started.

Kay is a collector from another era of mineral collecting, when thousands and thousands of old classics were recycling from old collections in Europe, and the mineral collecting market (and prices) was in its infancy. Many mineral collectors were academics, or affiliated with museums, and most collectors pursued minerals of their local area. She was hooked in 1928 at the age of 8 and collected for over 80 years - always a purist, collecting for the enjoyment and intellectual sport of it, with no regard to minerals as a longterm investment (though they came to be, anyways!). She pursued mineral collecting as a stress release from her world of high end art dealing in Europe and the USA, never spending the money on minerals that she spent on old tapestries and textiles, but perhaps spending more time. Her collection eventually ballooned to 13000 specimens at the time I bought it (she is 97 now). Until the 1990s, she forced herself to keep to collecting as a fun hobby, not an investment, by setting a price limit to what she would spend ($35 per piece went far in 1950; not so far by 1990). Despite her discipline, friends sometimes found ways to evade her price radar by giving her suspiciously good deals or trading to her benefit. I see many specimens from Scott Williams and Walt Lidstrom in her collection that really should have been priced more than she paid. Peter Embrey of the British Museum seems to have gone out of his way to give her oddly generous "house gifts" or trades of $5000-plus specimens on his visits to her home in Los Angeles over the years (including a number of old classics like German Mimetites and a Kongsberg silver). She once so desired a specimen of samsonite, lacking a good one in her otherwise comprehensive German suite, that Embrey trimmed off a 1 cm crystallized piece from the holotype specimen in the BMNH, and gave it to her as a gift (I have now repatriated this piece back to a friend in Germany where it belongs, she was happy to hear).

The Arkenstone's Dr. Robert Lavinsky met with collector Kay Robertson with a serious note to take care of many of the precious old labels accompanying her specimens. Kay Robertson made sure Dr. Rob Lavinsky was given a stern warning to take care of her precious minerals and the historic labels that accompany them.

She still has, to this day, the first major specimen of her collection, a remarkable German Sylvite specimen given to her by a Prince of some kind, when she was 8 years old and living in a grand old mansion while her father was the German diplomat to Venice. It sits in her living room where she sees it every day. It started a love of German and European classics that lasted her whole career, and she has built a trove of the kinds of rare old locality pieces available in the 1950s-70s and completely unseen for sale today. She used the collection as a study collection, and invited select collectors and academics to do so as well, eagerly participating in the discovery of new species and the identification of German classics from others' collections. She is probably the single most knowledgeable person today on the German classics, I would guess (she even got the best of Mark Feinglos in a trade once, on a rare German copper - and he definitely knows his stuff!). She speaks romantically of all the decades of travel to Europe, where she visited the museums, the collectors, and many of the mines before they were lost to history. She had a particular love of Hagendorf, and the new mineral Kayrobertsonite was recently named in her honor for amateur contributions to systematic mineralogy by Tony Kampf, and comes from Hagendorf.

I first met Kay in Tucson in the early 1990s ( I had gone since 1991, but she has gone since the 1960s!). I only knew her then as the "German lady who knew way more than I did" about pretty much all minerals. I was lucky enough to get to know her better after I moved to San Diego for grad school in 1995, and saw her at the local shows 3 or 4 times each year. I must have passed her test because I was invited to see the collection in 1997 for the first time, and I know that few had the privilege. For all her gregariousness at shows, she let few into her home. In those few visits in the 1990s, I learned an enormous amount about the old classics, about silver species, German rarities, and the thrill of collecting intellectual old oddities as opposed to only trophy species. She helped teach me to appreciate the micro as well as the macro, and her stories about the labels and the history of each piece convinced me of the value of provenance to specimens (as you will see in our updates of the collection, we tried to document and pass on all the information she gathered). A collection like this is impactful in sheer massiveness of the accumulated information and importance, and takes time to digest even on a quick skim. (Usually, 2 days at a minimum, and she was happy to talk the whole time about it all. ) While not full of trophy display specimens, every drawer had something that blew me away, especially as I had a lot to learn about the classics at the time. All of her minerals were stored in custom cabinets, with crammed drawers, mostly of wood and lovingly made by her husband for her over 50 years ago.

Decades of acquiring fine minerals filled custom-made drawers. Drawers upon drawers of fine minerals fill Kay Robertson's home, many in drawers and cabinets custom-built by her husband.

Kay's priority for the collection was to make it a reference suite and a teaching collection for those who needed it. She worked on several mineralogy projects, including a study of xanthoconite and the Hagendorf phosphates. Kay intended for the last 40 years of  her life that this collection would be her legacy to mineralogical education and to the museum of Los AngelesCounty, specifically. (Believe it or not, she actually curated their world textiles exhibit back in the late 1940s, before she was known as a collector!). She became lifelong friends with curator Dr. Tony Kampf, and promised them the collection. Much to her surprise, she has outlived her other assets and is in excellent mental health, and remains in her home with healthcare assistance. She recently made the difficult decision to sell the collection instead of donate it, as intended.

Obviously, this was not her initial plan, but she said to pass on that she takes comfort in knowing that her pieces will be shared with other passionate collectors around the world - the next best thing to going into a museum study room, in her mind. I knew that she felt conflicted about this, and so Tony Kampf and I met at her home one day in December of 2016 to present a proposal to her: I would buy the collection with the express intent of then donating a section of the value to the LA County Museum myself: the important Hagendorf reference suite; the micromounts; the major California pieces (save only one stibnite); and most of her more modern acquisitions of common species that they could have a use for in exhibits or outreach programs. Tony (now curator emeritus) and his colleague Alyssa Morgan, current collections manager, came and helped us pack at Kay's home. They returned to the museum with a moderate sized SUV vehicle, stuffed to the gills with mineral flats. So, in the end, a part of the collection is in museum now as we speak.  (see photo of smiling curators doing the hard and glamorous work of packing thousands of specimens, the bane of the the modern "international mineral dealer," in the LA heat).

Kay Robertson owned thousands of minerals, and many of them have been relocated to the LA County Museum. Tony Kampf and Alyssa Morgan assisted with packing up a large portion of Kay Robertson's collection to add to the LA County Museum's collection.


Carl Acosta, mineral collector, assists The Arkenstone in packing Kay Robertson's collection. Mineral collector Carl Acosta assisted with packing Kay's collection (and went home with a few new specimens, as well!)

Our good friend, LA-area collector Carl Acosta joined us for the packing, and to make deli runs for Reuben sandwiches to Famous Deli on Pico, nearby (he is really good at making food runs!). I'll admit here, that he took an awfully long time to pack the garnet drawer and probably would have been more efficient if I had not told him he could buy a few...

Kay's own life story can be found in wonderful prose, here, written up by the Mineralogical Record far better than I could do it justice now in a piece featuring her collecting history. Additionally, her granddaughter has launched a Facebook page to share details and stories regarding special pieces.

I am honored to announce that we have agreed with her family and Rainer Bode, editor of MINERALIEN WELT in Germany, to publish an extended issue (with dozens of pages dedicated to the Robertson collection) of the magazine in German, her native tongue, on her collection and her life. Although many Americans and curators know her collection, few Europeans have seen the specimens and visited her home, and she wants to share it with the larger world of collecting. Look for this extended edition to come out at the Munich show or soon after, of 2017. It is a small and long-deserved tribute to a passionate collector and her legacy, and deserves to be shared.

Explore fine minerals from Kay Robertson's collection now for sale.



The Ammonite: A Glimpse into The Past

Apr 11, 2017
This unique pyrite shell photo is great for wall art or as mineral canvas photo prints. Long ago, pyrite filled in the fossil remains of an ancient creature similar to a large snail. The result is this fantastic work of natural art - a pyrite mineral specimen in a truly unique form. Joe Budd Photo

Few places on earth hold as many mysteries as the ocean. Much of our understanding about the history of the deep ocean comes from studying fossils like the ammonite and the rocks where they rest.

The ammonite was a warm sea mollusk creature that lived between 200 to 140 million years ago, during the Jurassic Period.[1] Their soft protruding bodies resembled the modern-day octopus or squid with a hard-coiled shell (like the nautilus) that would make up half its total length.

Paleontologists believe the ammonite spent most of their life in shallow waters. The thin plating that sealed their 26 chamber walls were made of mantle tissue, allowing the soft body to retract for protection. This structure made it unlikely for the shell to sustain the high pressures of the deep sea.

Being a warm shallow sea creature, geographers use the ammonite as an index fossil when determining the age of rock layers. To be an index fossil, a specimen will need to meet four criteria:[2]

  1. Must have a wide distribution
  2. Must be found in various parts of the world
  3. The species must evolve quickly
  4. Must be easy to recognize

The Fossilization of Ammonites

When some people think of fossils, the first image that comes to mind is the tall skeleton of a tyrannosaurus rex. While all fossils are the remnants of an organism like bones, shells, and leaves, this includes remnants of activities like burrows and footprints.

Ammonites are more likely to create a fossil because of their hard shell. After the decomposition process, the shell is buried under sediment where chemical alteration or replacement and compaction occur. These shells have been found to survive tens of millions of years without damage.

Skeletons and shells containing calcium carbonate are replaced with calcite or aragonite to preserve its newfound shape. However, aragonite is unstable and more likely will dissolve away overtime than calcite, leaving behind a mold of the fossil. The empty molds that are left behind are likely to take in new minerals like silica or pyrite, creating intricate ammonite-shaped mineral pieces.

Natural ammonite from Calgary, Canada with rainbow coloring Ammonites found in Canada can have a unique iridescent, colorful appearance that is often used in the creation of ammolite jewelry.

Mythical Ammolites

In rare instances, an ammonite is opalized by minerals coating and replacing the organic material through the veins of sedimentary rocks. Opalized specimens shine the same colors as an opal with flares of red, yellow, green, and blue. These ammonites were given the name “ammolite” in 1981 by the World Jewelry Confederation.[3]

There have been famous instances in history where the discovery of ammolite specimens would spur legends of dragons and serpents. In the Middle Ages, ammolites were thought to be “draconites” – a mythical gemstones from the head of dragons.[4] In 7th century Ireland, ammolites were thought to be the “snakestones” cast away by St. Patrick.[5]

Ammonite fossils give collectors a glimpse into an ancient earth where the climate was warmer and ocean front were full of life. The ammonites were quick in adapting to their environment, allowing a variety of shell shapes and sizes. Some ammonites like the parapuzosia seppenradensis grew to a diameter of 11 feet, making them a fearsome creature of the ancient sea.[6]


Interested in adding an ammonite to your collection? Follow the Arkenstone on their many mineral shows throughout the year! Information on the shows we’ll be attending can be found on our Mineral Shows page. We’d love to meet with you and talk about the specimens in our collections!

Also, we’ve recently updated our galleries with many impressive specimens from around the world. You can find our latest collections here.

[1] “Ammonites”. British Geological Survey.

[2] “The Rise And Fall of The Ammonites”. Fossil Facts and Finds.

[3] “Ammolite”. Alberta Geological Survey.

[4] “Ammonite Gemstone Properties”. Shimmerlings.

[5] Alfred K. “Ammonites, legends, and politics”. Academia.

[6] “Museum of Comparative Zoology”. Biodiveristy Heritage Library.