Secret Superstars : Rare Rocks and Minerals (Part 2)

Secret Superstars : Rare Rocks and Minerals (Part 2)

No matter the country, the discovery of rare rocks and minerals is celebrated worldwide. This holiday season, we’d like to showcase a few of our favorite oddities – rare rocks and minerals we’ve discovered while building our own collection. We hope that by helping our readers familiarize themselves with these rare beauties, we’ll inspire other collectors and enthusiasts to get our and explore!

Take a moment to learn more about a few of our favorite rare rocks and minerals, below. We know you won’t be disappointed!

Diaboleite

Diaboleite [ Pb2CuCl2(OH)4 ] is a gorgeous mineral with deep blue coloring, which occurs in manganese oxide ores. It has also been found as a secondary mineral in lead and copper oxide ores, and in seawater-exposed slag. First discovered at Higher Pitts Mine in the Mendip Hills of Somerset, England in 1923, diaboleite has since been located Australia, Austria, Chile, France, Germany, Greece, Iran, Italy, Russia, South Africa, the UK and the US. It is generally associated with atacamite, caledonite, boleite, cerussite, hydrocerussite, leadhillite, chloroxiphite, mendipite, phosgenite, paratacamite, and wherryite.

Though Diaboleite generally exhibits a deep blue coloring, it appears pale blue in transmitted light. Its tabular crystals form as subparallel aggregates, or with massive habit – ranging up to 2 cm in size. Larger crystals are extremely rare, and very few quality specimens are found on market.

The luster on the fresh, deep blue cleavage faces of the Diaboleite is excellent, and much better than can be picked up in the pics.

A rare lead, copper chloride, Diaboleite is one of the great treasures from the surprisingly complex suite of minerals found in this old mine at Tiger, Arizona.

Anapaite

Anapaite [ Ca2Fe2+(PO4)2·4H2O ] is a rare calcium iron phosphate mineral. It is generally found within the cavities of fossil-bearing sedimentary rocks, or in phosphate-bearing iron ores – adding an element of environmental interest which makes it very appealing to collectors.

Despite the abundance of most iron phosphates, Anapaite is extremely rare. Its crystals commonly occur in rosettes or drusy crusts, with gorgeous coloring, ranging from olive green to milky white – though crystals may appear pale green or colorless under transmitted light. Named after its type locality in Anapa (Taman Peninsula, Russia) – some exemplary specimens have also been discovered in the  Ukraine, and Spain.

Anapaite crystal from Kerch, Crimea, Ukraine.

An exceptionally rich and aesthetic small miniature, of this very rare phosphate, Anapaite.

Boleite

Boleite [ KPb26Ag9Cu24(OH)48Cl62  ] is a very unusual and complex halide mineral – a crystallized lead-silver-copper chloride. Classified under the isometric crystal class, the external properties of boleite crystals strongly indicate its cubic structure. Its cubes consist of pseudo-octahedral tetragonal dipyramids, often measuring more than half an inch on each side. Despite its deep, glossy, dark blue coloring, it exhibits a light greenish-blue streak, and may appear almost turquoise in transmitted light.

Named for the type locality, Boleo (near Santa Rosalia, in Baja California), Boleite was first discovered in 1891, though it was then described as an oxychloride mineral. It is often associated with other rare rocks and minerals, including atacamite, anglesite, cerussitecumengeite, gypsum, phosgenite and pseudoboleite. When combined with cumengeite, boleite crystals may form a beautiful 3-dimensional “star” shapes.

Cubic boleite crystal for sale from iRocks.com - Baja California, Mexico crystal

A razor-sharp cube of precisely 1 cm, large for the species, and centered nicely to make the perfect thumbnail!

Rammelsbergite

Rammelsbergite [NiAs2 ] is a nickel arsenide mineral which occurs hydrothermally in medium temperature veins. First described by James D. Dana in 1854, after discovery of its type locality in Saxony, Germany – this rare mineral was named in 1855, in honor of German chemist and mineralogist, Karl Friedrich August Rammelsberg.

Rammelsbergite is often associated with skutterudite, safflorite, lollingite, nickeline, native bismuth, native silver, algodonite, domeykite and uraninite. Its orthorhombic prismatic crystals are typically massive in form, and exhibit coloring ranging from silvery-white to red, with metallic luster. Rammelsbergite is quite difficult to distinguish from related nickel sulfides and arsenides, though its unusually high hardness and silvery coloring helps. It exhibits a Mohs hardness of 5.5, and specific gravity of 7.1.

This rare grey rammelsbergite crystal was found in Russia.

Rammelsbergite is a nickel arsenide from the Lollingite Group. It forms tin white, metallic, stubby, orthorhombic crystals, occasionally it forms radiating botryoidal aggregates.

Zunyite

Zunyite [Al13Si5O20(OH,F)18Cl] is a sorosilicate mineral, composed of aluminium, silicon, hydrogen, chlorine, oxygen, and fluorine. Zunyite is so rare in nature that American Mineralogist has stated that “any information regarding a new occurrence… seems worthy of record.”. Zunyite’s crystallography is Lsometric, twinned, and typically exhibits tetrahedral form – though it is also found very rarely in octahedral formation. Zunyite crystals also fluoresce under UV light, emanating a beautiful bright pink to orange hue.

A 1986 discovery in a prospect pit near Quartzite, Arizona revealed enormous crystals, measuring up to 2cm. Many of these crystals are perfect tetrahedra, of a pale beige or tan hue, embedded in matrix – though some minute areas of these crystals were reported to be colorless, transparent, and of gemstone quality. Some Japanese locales may also include cuttable material, however this has not been confirmed.

Zunyite fine mineral specimen - rare crystal from the Electric Meatball pocket!

Zunyite from the famous “Electric Meatball” claim in La Paz, Arizona

 

Missed Part 1? Read the blog post here!

If you’d like to view more rare rocks and minerals, take moment to peruse our current collection of rare and unusual species – or contact the experts at iRocks, for more information on our upcoming auctions and shows!

 

An Introduction to Native Metals

An Introduction to Native Metals

Native metal is a term used to describe metals discovered in their natural, elemental form – either as an alloy, or in pure form. The list of metals which can occur in native deposits is long, though very few can withstand the natural processes of weathering and oxidization.

Most native metals (including aluminum, arsenic, bismuth, cadmium, chromium, cobalt, iron, lead, mercury, nickel, selenium, tin, titanium, tungsten, and zinc) are highly reactive when exposed to water, light, and other elements of nature – which means they are more likely to occur as small, isolated pockets of reduced ore, or as small flakes or inclusions.

Gold, silver, copper, and platinum are the least reactive of native metals. This greater capacity for endurance means they are the most likely native metals to be discovered in larger deposits – and their wider availability and occurrence offers a variety of interest to collectors. We’ve outlined some of their qualities, below.

Gold (Au)

The most familiar of native metals, gold has long been prized for its beauty, and rich yellow coloring. Its low melting point (approximately 1063’C) and malleable nature made it ideal for use by early cultures, adding to its perception as a valuable and precious material. Its high density lends it great weight, compared to most sediment – which means riverbeds have historically been an excellent place to locate smaller nuggets, grains, or flakes from placer deposits. Still, most mined gold is actually extracted from ore – often, from beds of white quartz or iron-laden rock, which is crushed and processed to remove gold traces – though it can also be found in larger veins, embedded in rock matrix.

Shop Gold Crystals

 

Silver (Ag)

Native silver is also considered a precious metal, whose brilliant white coloring, easy workability, and resistance to atmospheric weathering has made it a practical choice for use in trade, coin, jewelry, and ornamentation. It generally occurs in nature as an irregular mass, or in elongated, dendritic coatings – though it may also occur in cubic, octahedral, or dodecahedral crystalline formations. These can sometimes appear as nuggets or wires, such as in the photo above. Gold and silver alloys are often common – as are amalgams of silver and mercury. There are also a large number of silver compound minerals, such as tetrahedrite and argentite. Most silver is mined as a by-product from ores processed to obtain lead, copper, or zinc, and is recovered through a process of smelting and refining.

throughout the world.

Shop Silver Crystals

 

Copper (Cu)

Copper is a native metal whose use by Native American civilizations can be dated back to between 6000 and 3000 BC. Stronger and harder than gold, it was still soft enough to be useful in the creation of tools, fishhooks, and other useful items – which made it very valuable to those who collected it. Its rich coloring makes it easy to identify – though it ranges from a bright, pale rose hue on fresh surfaces, to a deep brown or bright, oxidized green under longer exposure to the elements.

Copper generally forms in basic volcanic rocks, and in the reducing environments of sulfide deposits. Its usual habit is dendritic and massive, though it can also form wires. Crystalline formation is rare, but will generally develop as cubes, octahedra, or dodecahedra. The spectrum of copper minerals closely resembles that of silver, and natural alloys of copper and silver are not unusual – though native copper still comprises a significant percentage of the copper minerals discovered throughout the world.

Shop Copper Crystals

 

Platinum (Pt)

Platinum is the rarest and most expensive of popular precious metals – even more so than gold. It’s white-metallic coloring is very fine, and it may closely resemble silver at first glance. It is extremely rare to find platinum in pure form; most native specimens contain traces of iron, and it is likely to be found associated with other elements such as gold, copper, and nickel, in alloyed form, or laced with other rare metals.

Platinum is the least reactive metal, and exhibits remarkable resistance to corrosion, even at high temperature – making it extremely valuable for industrial use. Due to its value, show specimens are scarce, and platinum is rarely represented in mineral collections.
Though these less-reactive metals may be discovered in varied sites of origin or locale, most other native metals are found only in very small quantities, or in very specific geographic locations – making them exceptionally rare and interesting specimens.

Platinum from Siberia, Russia.

Crystallized platinum is exceptionally rare.

 

Interested in learning more about the collection and occurrence of rare species and native metal specimens? View our current selection – or contact the experts at iRocks, today!

Sapphires: The Stone of Nobles

Sapphires: The Stone of Nobles

Fine Sapphire Crystal, Sri Lanka.

Natural sapphires like this one are judged on criteria like crystal shape, color, and the rarity of the location. Joe Budd Photo.

Since the ancient Greeks, Sapphires stones have symbolized social status and power. Sapphires are considered one of Earth’s precious stones for its rarity and beauty. Its brilliant blue color has been sought after by great civilizations around the world and continues to be one of the most popular gemstone quality minerals today.

The Sapphire: A Rare Beauty of Nature

Sapphire is a blue variety of corundum, and it is directly related to the Ruby. Like Ruby, it is made from crystalized aluminum oxide compounds. The only difference between a Sapphire and a Ruby is their color, which is developed from its impurities.

Most Sapphire specimens get their well-known blue color from trace amounts of iron and titanium in the crystal lattice. However, Sapphire stones can come in a spectrum of colors like pink, yellow, and green. These non-blue specimens are known as “Fancy Sapphires,” and they are much rarer to find in nature.

Sapphire Stones in Early History

Sapphire stones are only found in a few locations, including Cambodia, Burma, India, Kashmir, and Sri Lanka. Although there are few sources for mining Sapphire, the stones are referenced in many religious books and beliefs as symbols of truth, faithfulness, and nobility.

The Talmud & Mishnah of Orthodox Judaism describe the Ten Commandments of Moses as being inscribed in tablets of Sapphire. It is believed that Sapphire stones were chosen because they represented the throne of God and the color of Sapphire was “like the very heavens in its clarity.”[1]

The ancient Greeks believed that carrying Sapphire stones into Delphi amplified the wisdom of the questioner when consulting the Oracle at Apollo’s Shrine.[2] The Sapphire stones would clear their minds, allowing them to better understand the answers given.

The origin of Sapphire stones was of particular interest to the ancient Persians. The Persians believed Earth sat on top of a massive Sapphire pedestal whose blue color was reflected into the day’s sky.[3] The Sapphire stones found in the Earth were thought to be broken chips from the pedestal.[4]

Logan Sapphire Brooch, Smithsonian Institution

The Logan Sapphire Brooch in the National Museum of Natural History (Smithsonian Institution) – Chip Clark photo.

Famous Sapphire Stones

The Smithsonian National Museum of Natural History hosts one of the world’s largest faceted blue Sapphire – The Logan Sapphire. The gemstone was mined in Sri Lanka and weighs 423-carats, making it the heaviest mounted gemstone in the collection.[5]

While The Logan Sapphire is incredibly large for a gemstone, the title of heaviest stone goes to the recently discovered Star of Adam. The Star of Adam is a rare Star Sapphire weighing in at 1,404 carats.[6]

The Star Sapphire is a special variety of Sapphire stone that has an asterism in the shape of a six-pointed star-shaped that appears on its polished surface. The asterism comes from needle-like inclusions that intersect at varying angles. When light enters the stone in a certain angle the asterism becomes visible.

The Sapphire stands as one of the most sought after precious stones. The corundum makeup of the Sapphire can develop many unique colors, including the color Ruby. Yet, finding Sapphire specimens with deep shades of blue is especially rare, and it is one of the most referenced stones in history.

 

Want to see these rare stones and gemstones in person? Then checkout our expansive collection on our website. We’ve recently updated our galleries with many impressive specimens from around the world. You can find our latest collections here.

Also, don’t miss our listings for our rare rock and mineral shows. We’d love to meet with you and talk about the specimens in our collections!

[1] Ex. 14:10 NAB

[2] Diane M, Ancient Secrets and Modern Myths from the Stone Age to the Rock Age (Indiana: Greenwood Press, 2008), 167.

[3] Stephen V, The Great American Sapphire (Virginia: The University of Virginia, 1985), 48.

[4] Ibid.

[5] “Logan Sapphire”. Smithsonian National Museum of Natural History. http://geogallery.si.edu/index.php/10002687/logan-sapphire

[6] Lin T. “World’s largest blue star sapphire”. CNN. http://www.cnn.com/2016/01/05/luxury/worlds-biggest-blue-star-sapphire/

The Adelaide Emails, John Cornish in Australia – 5 of 5

The Adelaide Emails, John Cornish in Australia – 5 of 5

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

5/13/2014

It’s 9:28 pm. It’s been a long day.

As usual, we arrived at the mine at 9:30 this morning. Uncharacteristically, we worked late tonight, until 7:00 pm (our typical quitting time is around 5:00). At this point, now, Bruce has come and gone and I’ve finished showering and have eaten dinner. After finishing here, I’ll watch a movie or something to kill the time before finally I’ll call it quits and will head off to bed.

This morning, on the way in, I spooked two black cockatoos from one of the trees along the old Dundas road. These are large birds, beautiful, loud and entertaining. Very much I enjoyed watching them a’ wing, as for a moment, they flew just ahead of the car before arcing away and disappearing among the greenery. After that and almost at the mine, I spotted one of the two Wallaby’s I’d see today, one on the way in and the other, while driving out this evening.

Today was an intense day of serious “ups” and disappointingly serious “downs”, and bummer, things were going so well too…

After talking things through this morning, we both headed underground, Bruce and I, and took some photos and fine-tuned our work plan. When finished, I took the lead and began work on what would become a spectacular 20 inch long by 15 inch wide plate of glowing orange crocoite, one from down-low on the far-side of the “Refrigerator Rock”.

To realize my goal, I’d need to do some work…

First, I cleared a slot between Mother-Tasmania and my hoped for specimen, on the specimen’s left hand or its Foot-Wall side. While doing this, I recovered a flat-and-a-half worth of mediocre specimens. With that completed, next I whittled and cut, pried and sawed two lines, one vertically along the Hanging-Wall at a point suggested by Bruce (to minimize the damage where the plate would separate when collected), and the other, a horizontal line across the “top” of the specimen where I hoped to separate and liberate the plate from the mountain.

The “top” here is a kind of false identification. For this specimen, even at 20 by 15 inches, it could have been much larger, why it wasn’t would be due to the intimate contact shared between the matrix “Refrigerator Rock” and the hanging, overhead “Death Rock” precariously positioned against it.

By limiting the plate’s size, I’d be able to extract the part of the crocoite exposed below this critical contact point so as to leave everything there attached, in-place, and me happy and safe! This was my goal; this is what I set out to do.

It took me awhile, but everything was going perfectly and thus after a spell, it was time to go get Bruce, to help bar down the specimen, hopefully into my waiting arms…

Like the last big plate we recovered, I’d have to wedge myself in under the plate to support it when it broke free with the force exerted by Bruce’s bar action. To do this, I created a raised platform for me to sit on, bringing me in close and snuggled in tight. Once positioned, I directed Bruce to drive the bar into a solid area I’d noted, to securely lever against. He plunged the bar in forcefully, finding a solid purchase point, and there began his downward levering action.

With very little to-do or fanfare, it wasn’t long before the rock gave way under Bruce’s exertions and the crystal covered mass I’d set my sights on broke free and dropped gently into my waiting arms. Bruce was right there to help once I’d taken on the weight, to help pull me back, allowing me the impetus to bring the specimen around to a safe position where it could be set down securely.

Hearts pumping, smiles twinkling in our headlamp’s glow, we’d done it, another flawless extraction… Yes!

With photos taken, it was time to bring our big new prize out from the pocket-zone and the underground. The easiest way to do this, load it into the wheelbarrow and roll it out slick-as-slick-can-be! Outside, we took more pictures.

Read about mining adventures in the Adelaide mine with John Cornish

Rocks rock! John is especially proud of excavating this giant crocoite specimen from the Adelaide mine. Photo courtesy of John Cornish

Satisfying…. Fun… Productive… Successful… Yay!!!

Exhilarated and buoyant, riding the wave, after, we broke for lunch.

With this plate removed, the area we were working opened dramatically, revealing the position of the “Death Rock” to better advantage and also exposing an exceptional crocoite plate awaiting extraction, currently at rest upon the Hanging-Wall. This would be our next area of focused recovery.

With lunch over, Bruce and I headed back into the mine to assess the best way to extract the Hanging-Wall plate. We both took our time and shared our best most insightful thoughts and then, that done, I set to work (Bruce was kind, offering me the lead).

I had a tiny bit of rock I wanted to remove prior to working towards the plate, well over a foot away from the closest crystals. To do this, I started up the generator and powered up the hammer. Ready, I set the hammer to the stone and seconds later, before the rock I was working even had a chance to crack, the entire plate, that exquisite beautiful perfect plate covered in glowing orange crystal perfection on the pocket’s Hanging-Wall fell, dropping like a stone, down to the ground below where all of its crystals crushed in a broken heart’s beat.

Stunned, the hammer still rattling in my hands, I just sat there and stared, incredulous and dismayed. After a time, I shook my lethargy and switched off the hammer. Like picking up broken babies, I gently lifted the crushed specimens from the dirt and hauled them outside to show Bruce. He was as blown-away as I was, neither of us saw this coming, even though the Hanging-Wall has a history in this pocket of producing specimens lightly and precariously attached to its surface, this plate looked sooooo secure.

Disappointed, saddened almost to the point of tears, I took a break from collecting.

Quietly, solemnly, Bruce took up the tools after.

Bruce recovered nearly two flats worth of specimens before we called it quits for the day, collecting them from the underside of the Death Rock. By collecting these now, we’ll have a chance to produce, while staying out of harm’s way, many lovely specimens, unless of course the rock drops (which it appears likely to do at any moment it is so precariously and dangerously hanging).

And so, a little less enthusiastically than I’d hoped, our day finally came to an end. In the darkness illuminated by our headlamps we puttered about and gathered up our gear and then closed and locked the doors and set our sights for Zeehan.

The crystals affixed to the “Death Rock” will be there waiting for us in the morning (or they wouldn’t), for now, it’s been a long day.

This trunk-full of orange crocoite is only a small amount of the treasure collected by John and Bruce. Photo courtesy of John Cornish.

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 – 4 of 5

The Adelaide Emails, John Cornish in Australia – 4 of 5

We’re excited to have access to a special series of blog posts coming up written by by John CornishSpeaker 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.

 

5/12/2014

8:33 pm. Today was a great day and it went by way too fast! I’m a short-timer now, only a few days left before I go home, heading back to America. Feeling the pinch, I’m very much trying to maximize my efforts here. Sadly, the days just seem to fly by, fast, like I’m a kid counting the last days of Summer…

For Bruce and I, our day started pretty much as usual. We met at the mine, got the fire going, and discussed our stratagem for the day…

Yesterday had been a brutal physical day for me. I’d spent the majority of my time underground driving the hammer, raising the ceiling and cutting deeper into, above and behind, the “refrigerator” rock I’ve mentioned previously. My goal, other than to remove mass, was to punch into the pocket up high, above the rock, so as to figure from a different more advantageous position, the best solution to pursue to collect safely the incredible crocoite crystal groups generously covering the surfaces of several areas surrounding.

In performing this task, right at the end of the day, at the highest area of our raise, I hit a super spongy area where the hammer just dove into mucky-clayey-rock-and-crocoite-goo. Some of this I’d peeled and scraped away, but everything just seemed, just felt “right”. I knew the pocket lay just beyond.

But, it was late, everything would have to wait until the morrow…

Well, the morrow is now today and it’s time to get to it!

I went underground first and shot some pictures and then after, Bruce went in to get his shots. That done, we next set to extracting a killer, precariously hanging large plate of stunning, perfect crystals from the bottom area of the refrigerator. We’d recovered a killer specimen the day before from this area, it was over a foot across in both directions, bright-orange and perfect.

As we’re going after it today, this new specimen would be even bigger!

Bruce had the lead. Utilizing open space I’d made with the electric hammer, he used a saw to back-cut and define the large specimen. When satisfied, and after a little adjustment here and there, he was where he wanted to be and satisfied, he backed away and it was my turn to step in. I’ll be catching this time. We’d left the muck pile high so I could position myself directly beneath the pocket, resting on an over-turned flat’s back-side. There, I’d brace my left arm a’top my left leg. By snuggling in tight, I was hoping to, attempting to, uphold and support the plate solidly. When positioned to best advantage, I called Bruce back in.

Bruce, while avoiding my fingers and head, positioned himself solidly and with some force, jammed the bar in deep, lodging it within the cut we’d made using the hand saw. It took several stabs to find the sweet spot, but once there, we made magic happen as he pried down on the bar, levering the plate away from itself and into my waiting hands.

This happened perfectly, slowly, one minute nothing and then next I heard the tiny grinding and then louder popping sounds as the rock cracked and snapped and then whooom, my hands were full and I’m holding a ton of treasure for all I’m worth!

Mining is dirty work underground in the Adelaide mine in Tasmania. Photo courtesy of John Cornish.

Once there, with that monstrous crocoite treasure in my arms, I was thrilled, energized, pumped. There was no way I was going to fail, to lose the piece, I had our treasure held solid. Bruce had done his job perfectly and had backed away with the bar when the rock split. When the specimen dropped into my hands, I was ready for it and while it was heavy and cumbersome, I was thrilled that I had it secure, tight, I just needed a tiny bit of help to complete my task and next ya know, there Bruce was, helping perfectly. Grabbing the specimen’s edges carefully as I’d instructed, and with me latched-on tight, Bruce pulled us both back, allowing me the room and momentum to twist the rock forward, around my body, to a perfect resting position.

With it down, we were elated, smiles and “Good jobs!” abounded. The specimen, originally all but hanging upside-down, was now down and out, we’d done it, another perfect treasure recovered! We snapped off a ton of pictures. It was approximately 15 inches across and absolutely stunningly glorious!

With the specimen down safe, after a breather, we next set to finishing the job and grabbed it up and carefully hauled it out towards the tunnel mouth. There now at rest, it’ll wait until the 14th or the 15th, when we’ll load it up into the Subaru in anticipation of my returning to Adam’s.

Satisfied, lunch followed next, bolstered by a hot cup of tea.

After, Bruce finished eating first and with me still munching away, he headed in and began working up high in the raise where I’d left off the day before. There, he found the soft, punky-area I’d mentioned. Five minutes of poking, prodding and prying later and he was looking into the growing maw of a large cavernous black void… Finally, we’d broken through above the refrigerator rock and my-oh-my, what a view!

Revealed in two different areas, above and ahead, we could see open space over a dozen feet away! There was some crocoite showing, especially as we opened the hole further (this included not just hand tools, but a decent spell with me driving the hammer to effect), making a body-sized opening which really allowed us a view within.

Crocoite pockets extend into the mountain in the Adelaide mine. Photo courtesy of John Cornish.

This was a very exciting time for us, we’d spent considerable time and effort looking for this feature, using our best insight, our hope and our belief to guide us. Vindicated, before us, a promised-land beyond our wildest expectations stretched into the darkness beyond.

And more, we’d made it here safely. Even as things had ramped up, challenge after challenge, we’d stepped up our game accordingly and together, we’re doing a great job!

What a day; a killer plate recovered, technical and difficult x 10, but we’d done it; and vindication, we found the target we’d set out to discover and in finding it, we’ve opened an entirely new level of the Red River pocket system, its highest yet!

Yes indeedy, fun x 10!!!

As a final compliment to the day, I saw two bounding and bouncing Wallaby’s while driving into the mine. I love seeing these lil’ guys!

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!

Revealing a New Facet of the Hope Diamond

Revealing a New Facet of The Hope Diamond

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

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

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.

 

5/6/2014

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

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

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.

 

5/2/2014

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

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

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.

 

4/27/2014

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

Won’t Be Fooled Again: Big Differences between Gold vs Pyrite

Pyrite cubes on white quartz crystals from Peru

A Peruvian treasure – striated pyrite crystals perch on quartz.

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”.

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. https://blogs.scientificamerican.com/rosetta-stones/famous-fools-for-fool-8217-s-gold/

[2] Ibid.

[3] “How heavy is a gold bar?”. Elmhurst College. http://chemistry.elmhurst.edu/vchembook/125Adensitygold.html

[4] “Pyrite”. Mindat. https://www.mindat.org/min-3314.html