Video: How Big, Beautiful Crystals Form by Dr. John Rakovan

Aug 8, 2017

Dr. John Rakovan

Dr. John Rakovan, crystallography expert at the University of Miami, Ohio, speaks at the 2016 Dallas Mineral Collecting SymposiumIn 2016, Dr. John Rakovan participated as one of our speakers at the Dallas Mineral Collecting Symposium, and the topics covered in his talk are ones we regularly address here at The Arkenstone.

How do crystals form with such geometric shapes? Why do some crystals get big, while others stay small? What controls the different crystal shapes that are formed naturally?

If you've ever thought about some of these questions, we hope you'll find Dr. Rakovan's talk to be informative.

Dr. John Rakovan is a professor of mineralogy at Miami University in Oxford, Ohio. John received his Ph.D. from the State University of New York at Stony Brook in 1996 and spent a year as a postdoctoral fellow at Virginia Tech before starting at Miami. He has broad research interests including crystal growth, structural and morphologic crystallography, mineral-water interface geochemistry, and mineral deposit formation. Much of his work falls into the broad area of environmental mineralogy. He is a fellow of the Mineralogical Society of America (MSA) and has served the MSA and other societies (e.g., the International Mineralogical Association) in many capacities including the subcommittee on apatite-group nomenclature. John has been a mineral collector for more than forty years with particular interests in apatite, minerals from Japan, and specimens with interesting mineralogical characteristics (i.e. twinning, epitaxy, etc.). He has been an executive editor of and regular contributor to Rocks & Minerals magazine since 2001. In 2010, the decavanadate mineral rakovanite, discovered by Joe Marty in the Sunday Mine, Colorado, was named in his honor.

The Dallas Symposium is lucky to have BlueCap Productions on hand each year to provide valuable videography services. If you love learning about fine minerals, check out their Video OnDemand options to view previous videos of the Dallas Symposium, the popular What's Hot in Tucson/Munich/Sainte Marie series, and several other popular mineral productions. Prefer hard copies? DVDs are for sale here.

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2017 Dallas Symposium – This Year’s Collection of World-Class Lectures and Speakers

Aug 5, 2017

The 2017 Dallas Mineral Collecting Symposium is a unique annual event that brings together mineral enthusiasts and experts from around the world to review the latest and greatest findings, collections, and forerunners in rare minerals. This year, the Dallas Symposium starts August 25th – 27th at the Eisemann Performing Arts Center and promises to bring forth the most exciting lineup of scholars, collectors and adventurers! Some of the lecturers presenting at the 2017 Dallas Symposium are:


John Cornish – Australian Crocoite Mining

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

An expert in all things crystalline and paleontological, John Cornish is respected for his contributions to field collecting. John is affiliated with several specimen mining properties in the western United States with many of his discoveries displayed in premier institutions and collections around the world. Currently, John is working on chronicling this 20+ year pursuit of mineral and fossil localities.

At the 2017 Dallas Symposium, John will share some of his adventures of successfully mining crocoite in Australia’s Adelaide Mine. His lecture will be accompanied be accompanied by a colorful and story-rich presentation, highlighting many of his historic findings and experiences in field collecting. (Check his blog series here that he allowed us to publish!)


Bruce Bridges – The Tsavorite Mine

Backlit Tsavorite Crystal, Copyright Bridges Tsavorite

As a third-generation gemstone miner and dealer in Africa, Bruce Bridges is making his name known throughout the rare mineral world as the President of Bridges Tsavorite company. His father, Campbell Bridges, was the discoverer of Tsavorite and was the first to bring Tanzanite to the United States for Identification. Today, the family business maintains its fully integrated operation, from mining to sales of rare and valuable minerals.

Bruce Bridges will give a rare first-hand account of the history of Tsavorite and the life of his father. The Bridges family’s expertise in geology and business have allowed them to pursue some of the rarest stones of East Africa. In addition to these adventures, Bruce will discuss the development of the famous Scorpion Mine and the growth of the Tsavorite mining industry in Kenya. Read more about the Bridges family at


Richard Hughes – The Secret World of Ruby & Sapphire

Designed as a companion to Ruby & Sapphire: A Collector's Guide, this massive volume is aimed specifically at working gemologists, appraisers and students. Based on Richard W. Hughes' 1997 classic, Ruby & Sapphire, this edition is fully updated. The product of nearly 40 years of firsthand experience and research, it covers every aspect of the subject from A–Z. History, sources, prices, quality analysis, synthetics and treatments, everything is here. With over 1000 photos, maps and illustrations and 3500 references, Ruby & Sapphire—A Gemologist’s Guide represents the most comprehensive book ever written on a single precious stone. Ruby & Sapphire • A Gemologist's Guide by Richard Hughes, a speaker at this year's Dallas Symposium

One of the world’s leading experts on rubies and sapphires, Richard Hughes has spent a lengthy career authoring several books and over 160 articles on gems and gemology. Over the years, Richard has received many industry awards.

Some of his most notable awards include the 2004 Edward J. Gübelin Most Valuable Article Award from Gems & Gemology magazine, the Richard T. Liddicoat Journalism Award from the American Gem Society, and the 2010 Antonio C. Bonanno Award for Excellence in Gemology from the Accredited Gemologists Association. Richard’s latest book titled, Ruby & Sapphire: A Gemologist’s Guide (2017) is his most comprehensive volume of work on rubies and sapphires to-date.

Attendees of the 2017 Dallas Symposium will have the special treat of hearing Richard Hughes uncloak the mysteries surrounding fine corundum specimens. Richard’s lecture will discuss the links between the mineral, their deep connection to human history, and their impact on life itself. Learn more about Lotus Gemology here.


These are only three of the speakers who will be sharing their expertise at the Dallas Mineral Collecting Symposium. If you're looking to learn about minerals, crystals, and gems, you don’t want to miss this year’s Dallas Mineral Collecting Symposium at the Eisemann Center, as experts, scholars, and adventurers from around the world come to share their latest and greatest findings! Registration for the symposium is open now and throughout the event. A Full Symposium Ticket includes all of the events listed above, including the open house cocktail party at The Arkenstone, Saturday’s lectures, lunch, benefit auction and banquet, and passes to the Perot Museum of Nature and Science.

2017 Dallas Mineral Collecting Symposium

Aug 4, 2017

Dallas Mineral Collecting SymposiumIt’s that time of year where rare mineral enthusiasts pack their bags and make their way to Dallas, Texas for the annual Dallas Mineral Collecting Symposium. This year, the 2017 Dallas Symposium starts August 25th – 28th at the Eisemann Performing Arts Center with this year’s event promising to be more exciting with larger events for experienced collectors and newcomers alike.

The 2017 Symposium will have several activities throughout the event, including an all-inclusive Saturday event, exhibits from your favorite collectors, and world-famous guest speakers, sharing their rare mineral discoveries and research. Speakers and their topics at the Symposium include:

Friday, August 25th, 2017

Full Symposium tickets to the Symposium comes with complimentary passes to the Perot Museum of Nature and Science, so if you come in town early, take advantage of the opportunity to visit one of Dallas's most important museums. The museum has five floors with 11 permanent exhibit halls, state-of-the-art video and 3D rendered animations, simulators and more. Don’t forget to stop by the museum’s expansive mineralogy and geology exhibits, hosting over 100,000 specimens.

Saturday, August 26th, 2017

The Symposium takes off with a full-day of lectures and Texas barbecue for lunch! After the day’s lectures, we invite attendees to enjoy a relaxing social cocktail hour, dinner banquet, and benefit auction. It’s the perfect opportunity to meet and speak with the lecturers and fine mineral collecting community – make new friends and catch up with old. If you have a +1 who would like to attend the evening event, social guest tickets will be available.

The lectures and lunch will all be held at the Eisemann Center, across the Renaissance Hotel. For information on booking your stay at the Renaissance Hotel, click here.

Sunday, August 27th, 2017

The Arkenstone Gallery invites you for coffee, bagels, and camaraderie with the mineral collecting community! The gallery will be open from 9AM-1PM, offering a relaxing opportunity to examine rare and exclusive pieces or purchase new ones for your personal collection. There will be smaller events held throughout the evening that are invitation only.

Monday, August 28th, 2017

If you're staying in Dallas a bit longer, this will also be the last day your Perot Museum of Nature and Science pass will allow you in for free. Don’t forget to partake in the museum’s many exhibitions and exclusive rare mineral and science collections.


We hope you’ll join us at this year’s Dallas Mineral Collecting Symposium at the Eisemann Center! Registration for the symposium is open, but we only have a short time before the symposium events begin. A Full Symposium Ticket includes all of the events listed above, including the open house community meeting at The Arkenstone, Saturday’s lectures, lunch, benefit banquet and action, and passes to the Perot Museum of Nature and Science.


Buying Rocks and Minerals Online

Aug 4, 2017

When Dr. Rob Lavinsky founded in the mid-1990's, it was simply an extension of The Arkenstone – the rock and mineral business he had been running since he was a young teenager. The site was the first of its kind, and quickly proved itself useful to collectors and enthusiasts worldwide.

Since then, iRocks has set the world standard for collecting rocks and minerals online – and we're here, today, to offer some smart guidelines for building your collection online.

The Arkenstone's Jeff Starr has a soft spot for fluorite, like this specimen from Erongo, Namibia in his collection.

Get specific. The internet is endless, so narrow your focus to the specimens which truly interest you. Whether you are focused on a specific species or locality, by narrowing the categories of your search, you'll receive a more manageable number of hits, and save yourself the time and effort of perusing specimens with low appeal to your collection. Not sure where to start looking? Check the themed galleries on iRocks for ideas on different areas to focus your collection! Here at The Arkenstone, we help collectors who have a wide range of collection themes; employee Jeff Starr focuses on fluorites (with some extra special outliers), while gallery manager Kevin Brown has an affinity for American minerals. Is blue your favorite color? Consider starting a collection of blue crystals!

Do your homework. Use the power of the internet to research rocks and minerals online. Mindat is an excellent resource for exploring, and can provide insight into interesting properties and localities, as well as providing extensive images of most known minerals.

Pay attention to provided photos. The best listings will feature several high-quality images, so you can view the specimen from all sides. The more detailed images provided, the better you'll be able to assess the quality and appearance of rocks and minerals online, and decide if each specimen meets your expectations. Take note of items included in images which might provide clues as to size and color, and ensure your monitor is properly calibrated to reflect color accurately.

In fine mineral photography, it's often necessary to take many pictures in your quest to produce the best fine mineral photographs. Multiple photos of this specimen from different angles help viewers learn more about the crystal.

Read the descriptions closely. The best listings will include accurate and informative descriptions, including any important historical notes or relevant details. At the very least, EVERY listing should include the mineral name, locality or origin of the piece, and size – as well as noting any damage or negative features. If you have questions which are not answered by the images or descriptions, contact the seller, and allow them the opportunity to address your concerns before bidding for rocks and minerals online.

Beware of forgeries and fakes. While the vast majority of auctioned rocks and minerals online are authentic, occasional trickery has been known to occur – generally in the form of man-made or “enhanced” specimens. Protect yourself from fraud by purchasing from well-known and established dealers and auction houses, and by educating yourself on identification of frauds and fakes. If a specimen has been repaired, potential customers should be warned upfront!

Verify the seller's reputation. Reputable dealers stick around! Reviews for those who consistently offer high-quality rocks and minerals online can easily be located – they have buyers who will attest to their integrity, the quality of their service and merchandise, and their commitment to customer satisfaction. If you are unsure if a seller is legitimate, ask around – your collector colleagues and contacts will be sure to lend some insight.

Read the policies and procedures. Before participating in an auction, or purchasing rocks and minerals online, review the seller’s policies and procedures to be sure you understand them, and that they're consistent with your expectations and needs. Pay close attention to return policies, and seek sellers who offer reasonable terms for requesting a refund. (As a side note – you should expect to absorb any costs for return shipping and handling, should circumstances require it.)

Account for shipping and postage. Shipping and handling costs can vary drastically, depending on the size and weight of each specimen and the distance of delivery. Pay attention to these charges when calculating the final cost of your purchases – and you'll avoid any costly surprises! If a shipping calculator is not provided, ask for an estimate of postage charges before confirming your sale – and avoid any sellers who do not respond, or provide a specific window for delivery.

For more information regarding collecting rocks and minerals online, check out our other informative articles – or contact the experts at iRocks, today!

Rutile: Mineral of Many Uses

Jul 30, 2017

Rutile [TiO2] is the most abundant naturally-occurring form of titanium dioxide. Long recognized for its value and use in manufacturing and industry, it has more recently gained recognition and popularity amongst collectors, due to its newly discovered ability to aid in rock and mineral research.

Rutile is an interesting mineral, with varied habit and presentation. It's name is derived from the Latin rutilus (meaning “shining, golden-red”), a reference to one of rutile's common habits – a deep red, lustrous crystal – though it occurs in a surprising variety of distinct and beautiful habits and colors. It appears in multiple unique crystal forms, styles, and associations. Twinning is common, and some rarer specimens even exhibit a unique habit known as the Rutile Star (a formation of crystals grown surrounding a hematite specimen, with six rhombic faces).

Golden Rutile crystals shoot out from hematite. Novo Horizonte, Brazil. Joe Budd Photo.


Rutile in Quartz from Brazil This cut stone shows the beautiful natural art of these rutile crystals included in quartz.

Rutile's coloring can vary greatly – from mirror-like metallic crystals, to bright golden needles – and it is well-known for its tendency to form slender, fibrous, or straw-like inclusions within other minerals. One beautiful combination is that of rutile with quartz (or Rutilated Quartz) – which is prized by mineral and gemstone enthusiasts. Microscopic inclusions of rutile within other gems (such as tourmaline, ruby, and sapphire) are often responsible for unique, internal light and optical effects which present as chatoyancy, or asterism – for example, that exhibited by Star Sapphire.

Rutile is the preferred source of titanium ore (a metal whose strength, weight, and resistance to corrosion make it ideal for use in high-tech alloys). It has also been widely used in the production of glass, porcelain, and ceramics, as it is a valuable coloring agent. It can also be used to add color to steels and copper alloys, and is valued for its usefulness as pigmentation in paints, due to its ability to retain its color, over time.

Despite its common occurrence and widespread use in manufacturing and industrial production, rutile has remained a relatively unknown mineral, until recently – when it was discovered to be particularly useful in rock and mineral research. Rutile's unique properties have proven helpful for gaining insight into the history and formation of other rocks and minerals, and its use by rock and mineral researchers has already contributed significantly to advances in the fields of geochemistry and geochronology.

Rutile on quartz from Azerbaijan. Rutile on Quartz - These came out in the late 1990s in one small batch, and are now rarely available. Surely they must be the best find for the species since Graves Mountain's heyday.

There is increasing evidence of rutile's value and usefulness in rock and mineral research. Microanalysis of tiny specimens of rutile can be used to decipher the timing and conditions of petrological processes, according to one recent scholarly article, and research spearheaded by Thomas Zack (of the Department of Earth Sciences, at University of Gothenburg) has identified a new method of laser ablation, which allows rock and mineral researchers to use rutile for in-depth analysis of specimens.

The process (called Laser Ablation ICP-MS) involves the examination of microscopic rutile inclusions to identify rutile-containing rock types, and reveal information regarding the changes in temperature and pressure to which they have been exposed, throughout history. This process not only reveals important information about the lifecycle and formation of these specimens, it produces results much faster than previous methods.

MIntergrown, reticulated, twinned rutile needles from Madagascar. Rutile from Madagascar. It is one of the finest examples of rutile that I have seen from the locale, though there were many of larger size. Joe Budd Photo

According to Zack, this discovery “is one of the most important analytical instruments at the Department of Earth Sciences here in Gothenburg.”

Rutile's new role as an aid in rock and mineral research is certainly adding interest for dedicated collectors and rock enthusiasts – increasing the value of this already fascinating and beautiful mineral species.

Love Rutile? Visit our gallery to explore rutile fine minerals and crystals for sale from The Arkenstone, or search for other minerals to fit your collection.

Secret Superstars : Rare Rocks and Minerals (Part 2)

Jul 28, 2017

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 [ 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 [ 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 [ 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 - 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 [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.

[caption id="attachment_5217" align="aligncenter" width="600"]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.[/caption]



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

Jul 23, 2017

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

Jul 18, 2017
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.

[6] Lin T. “World’s largest blue star sapphire”. CNN.

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

Jul 15, 2017

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.


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

Jul 13, 2017

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.



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!