CARBONATECYANOTRICHITE: ME CONFUSED

 

During my 2026 ramblings in Tucson looking for small goodies, especially those blue in color and stuck in Perky Boxes, I stumbled across a specimen of carbonatecyanotrichite. I took a quick peek with my hand lens and decided it had my name all over it. Without any other thoughts I presumed that it was cyanotrichite (Cu₄Al₂(SO₄)(OH)₁₂ · 2H₂O), a secondary copper mineral from the oxidized zone, with some carbonate thrown into the mix. In fact, when the mineral was first described (Ankinovich and others,1963), the authors noted it was a variety of cyanotrichite. In returning home and looking at the specimen of “cyanotrichite”, I decided that it: is a gorgeous mineral; the chemistry is complex; and my guesses are usually “wrong”. This entire, confusing situation reminded me of the great poet Robert Frost—I’m not confused. I’m just well mixed.

So, every curious rockhound then descends in a deep dive into the literature “trying to find answers to life’s persistent questions” (Guy Noir, Private Eye). However, PE Noir and I failed to locate many answers to anything and agreed with Hager and others (2009): “final resolution of the nature of individual members of the [Cyanotrichite] Group awaits single-crystal studies when suitable crystals become available… “ Those Group members (closely related, monoclinic Cu-Al-sulfates) include: cyanotrichite, carbonatecyanotrichite (usually with carbonate), camerolaite (antimony rich) and khaidarkanite (fluorite rich), a Co-rich member of the group from the Grandview mine, Arizona, and a cyanotrichite-like phase from the Clara mine, Germany.  Mills and others (2014) solved the crystal structure of camerolaite and suggested a structure for cyanotrichite. What Private Eye Noir and I learned from this deep dive is that although cyanotrichite and carbonatecyanotrichite were once thought to be closely related or even varieties, Hager (2009) pointed out that there is no evidence that a solid solution series exists between the two minerals. What we have is four, or more, similar minerals that are impossible to distinguish without the use of electronic gizmos such as a single crystal x-ray diffraction unit.  

So, since my single crystal XRD is on the blink, how do I know that specimen presented here, and collected from the Qinglong Mine, Qianxinan, Guizhou, China, is carbonatecyanotrichite? I am taking the word of my dealer, and from Robert Lavinsky who noted in MinDat that “the Qinglong Mine in Guizhou, China is the only confirmed source for the species in the entire country. Specimens started trickling out in the mid-2000s (originally labeled as cyanotrichite - but it should be noted that many of the world occurrences for "cyanotrichite" are turning out to be carbonatecyanotrichite upon analysis), and are very few and far between these days on the market.” Now I really appreciate the words of the non-geologist Winona Ryder: when you finally accept that it's OK not to have answers and it's OK not to be perfect, you realize that feeling confused is a normal part of what it is to be a human being.

As I noted above carbonatecyanotrichite is a stunning mineral with a sky-blue, or at times an azure blue, color. It is very soft at~2.0 (Mohs) and has a silky luster. Transparent to translucent crystals are acicular or needle-like in appearance. In fact, the root word of cyanotrichite is derived from the Greek words: kyaneos = blue and triches= hair.     

Mass of hair-like crystals of carbonatecyanotrichite. Width FOV ~ 7 mm. Arrows point to unknown minerals noted below. Mineral 6 may be darkest purple fluorite or limonite.

Number 1: spherules of a very dark, ?black “nest”. My best guess limonite, Number 3: ?tan crystals without a definite shape. Both are in a vug. The matrix appears to be quartz with a few patches of fluorite.

Mineral 2: bundles of dull white prismatic crystals. My best guess is baryte. Mineral 4: white balls less than .15 mm in size. Possibly calcite.

 

Mineral 5: prismatic black crystal of perhaps stibnite. The very slender crystal seems perched on limonite and covered with such.

This specimen has been a tough one to decipher as the non-blue minerals are tiny, all a fraction of a millimeter and beyond the limits of my scope. As Daniel Boone stated,  I have never been lost, but I will admit to being confused for several weeks.

REFERENCES CITED

Ankinovich, E.A., I.I. Gekht, and R.I. Zaitseva,1963, A new variety of cyanotrichite - carbonate-cyanotrichite: Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva: vol. 92.

Hager, S., L P. Leverett, and P.A. Williams, 2009, Possible structural and chemical relationships in the Cyanotrichite Group: The Canadian Mineralogist, vol. 47, no. 3.

Mills, S.J., A. G. Christy, C. Schnyder, G. Favreau, and J. R. Price, 2014, The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes: Mineralogical Magazine, vol. 78, issue 7.

BLUE MINERALS FROM THE DESERT: EFFENBERGERITE, KRÖHNKITE AND JUANGODYITE

I am missing Tucson 26 and all of the activity associated with the shows and presentations. After spending February and March in a Tucson VRBO our Wisconsin home was reached early April after an 1800+ mile drive in less than three days. I sort of just rolled out of the car seat since my legs seemed stuck in a funny position. However, the pleasures of my home abode soon overrode the thoughts of those lonesome Interstate miles of eastern Arizona, New Mexico, Texas, and Oklahoma! And, Wisconsin has trees and water, big water, as the upper Mississippi River is only about a mile from my home. But, Wisconsin is still cool to cold in early April with good chances of snow. What I really missed  was the Arizona spring weather-- the warmth of the evenings and the cool nights that offered clear skies with minor ambient light and many bright celestial objects, including the March total Lunar Eclipse and Blood Moon. During this event the Sun, Earth, and Moon were exactly aligned, leaving the Moon completely enveloped in Earth's shadow and, the Moon actually turned blood red. Above my VRBO Jupiter was bright and clear in the low humidity sky while Venus was very bright in the low western sky right after sunset. As for stars, I just followed the alignment of Orion’s Belt right to the Dog Star, Sirius, the brightest star in the night sky. On March 20, the Vernal Equinox,  I just plopped my derriere in a comfy reclining lawn chair and watched the night sky while dreaming about what might have happened decades and centuries ago at places like Stonehenge and Chaco Canyon. It doesn’t take much to make an ole guy happy! 

 The Upper Mississippi River near my home is about ~3 miles wide (alluvial floodplain ~5 miles) between the bluffs with the "main channel" (against the far western bluffs in Minnesota) and contains a wide variety of marshes, pools, and "back waters" (foreground) and looks much different than the levee enclosed ditch of of the Lower Mississippi south of St. Louis (where it picks up the Missouri River) and the alluvial floodplain is ~50 miles wide).

Lock and Dam #7 in the La Crosse area (Minnesota to the right, Wisconsin left). Interstate 90 bridge down stream. Photo public Domain.

 In addition, my hummingbird feeders were quite busy in the Arizona spring with at least three different species: Ruby Throated, Broad Tail, and Rivoli’s. An oriole hung around and sampled his own jelly plate. This latter bird is new to my list and arrived directly from Mexico: a Hooded Oriole. Here at home, I am still looking for the first goldfinch at my thistle seed feeder.

 

A friend visiting from Mexico, a Hooded Oriole. 

Readers of this Blog know that as a rockhound/collector ages: 1) mineral display space in their office and storage area decreases; and, 2) unless you have beaucoup bucks, larger, beautiful mineral crystals are best ogled at shows and in museums. But, several years ago a wise mineral collector told me about micromounts, including micros and thumbnails, and Perky Boxes. My collecting and buying habits immediately changed, especially when I purchased a cheap binocular scope online, discovered that many early members of my home Colorado Springs Mineralogical Society (CSMS) were micro collectors, found the Baltimore Mineral Club (home of the Micromounters Hall of Fame), noted that it does not take much space to store Perky Boxes, and that many/most micros display fantastic, often complete, crystals. Later in life I was able to purchase the Swift binoc of CSMS Charter Member Willard Wulff, and after several digital microscopes finally settled on a commercial Aven Mighty Scope. A few months ago, I took possession of a “super duper” AmScope with fantastic optics and a trinocular arrangement with camera. I am also trying to become a better photographer with a 35 mm camera with macro and micro lenses—the jury is still out with the latter setup. But as a lifelong learner I keep plugging away. Also, I continue to learn from my micro colleagues in the Baltimore Mineral Club, Canadian MicroMineral Association, and the Micromineralogists of the National Capital Area.

Readers also realize that I am partial to “blue minerals” as blue color is everlastingly appointed by the deity to be a source of delight (see January 26 post). Therefore, I spent time at the shows looking for blue minerals in Perky Boxes and now wish to document a few uncommon blue micros from Tucson 26.

Krohnkite is an uncommon, hydrated sodium copper sulfate [Na₂Cu(SO₄)₂ • 2H₂O], that forms in arid, oxidized zones of copper deposits. In fact, the type locality is the Chuguicamata Mine, Chile, in the famous Atacama Desert, and is the deepest (~3300 feet) and the largest open pit copper mine in the world. An AI article on Google described the Mine as a porphyry copper deposit (PCDs), one of the large-tonnage, low grade ore bodies associated with felsic magmatic intrusions and that are the world’s primary sources of copper. PCDs form in subduction-related convergent plate margins. The mineral deposits are created by metal-rich fluids associated with cooling magma chambers. As productivity of these large open pits slows down after decades of mining, some of the mine operations simply stop, while others such as the Chuquicamata switch to underground mining to reach additional deposits. Chile, with its many mines, produces over a quarter of the global supply of copper.

Kröhnkite is an uncommon hydrated sodium copper sulfate and the only good specimens come from the Chuguicamata Mine, Chile. Each specimen of this cluster displays the lamellar growth of crystals in parallel bundles best seen in the elongate form (length~1.0 cm) in right quadrant shown below. 

 Kröhnkite is not a mineable mineral but is attractive to collectors due to its color, sky-blue to pale blue to greenish blue to green with exposure to light, and its rarity. It is quite soft  (Mohs) with equant to short prismatic  Monoclinic crystals. At times kröhnkite occurs as crusts and granular aggregates. Crystals are vitreous and translucent to transparent. Interestingly, heating kröhnkite to about 400 degrees F will drive out the water and form a new mineral saranchinaite, Na₂Cu(SO₄)₂.  In the other direction, saranchinaite transforms into kröhnkite when exposed to open air at 87% relative humidity and ~77 degrees F for a week (Siidra and others, 2018).

And for a tongue twister, here is juangodyite, a sodium copper carbonate,  Na₂Cu(CO₃)_2,  whose Type Locality is the Santa Rosa Mine (described by MinDat as an adit within the now defunct Santa Rosa silver mining area), also in the Atacama Desert. The Chilean Desert is quite rich in mineral resources such as lithium, boron, gold, silver, iron and copper and contains the largest deposits of sodium nitrate (Chile saltpeter, NaNO₃). The latter mineral had a long history of usage as a major ingredient in gunpowder. In fact, the mining of sodium nitrate was the largest mining operation in Chile until the invention of synthetic nitrate in the early 20^th Century. Wars and border disputes were fought until it all blew up (not gunpowder) via synthetics and something like 175 towns and mining districts were abandoned. Today the Atacama is the major source of iodine-bearing minerals and of course copper.

The Atacama is known a the “driest place in the world” but also has a cold desert climate—mild temperatures with very little fluctuation and essentially a total lack of precipitation. It is a plateau stretching about 1000 miles situated between the Andes Mountains and the Chilean Coast Range which create a giant and permanent rain shadow.

Ultramarine crust of  juangodoyite ps. chalconatronite. Width FOV ~ 5 mm.

 

Enlargement better showing the <5 μm pseudomorphs of juangodoyite on tiny laths of chalconatronite Width FOV ~3.0 mm.  

 Juangodoyite is a rare, secondary mineral from the oxidation zone of polymetallic ore deposits. It is an earthy mineral with a vivid ultramarine color. It is a fine-grained pseudomorph (crystallites up to 5 μm in size) replacing chalconatronite, a hydrated sodium copper carbonate that usually occurs as thin laths (Na₂Cu(CO₃)₂ · 3H₂O). Due to the pseudomorph nature and the small size of the crystallites very few optical and physical properties are known.  Juangodoyite will rehydrate to chalconatronite within a few hours of immersion in water. MinDat only describes two localities for Juangodoyite: 1) the Type Locality Santa Rosa in Chile and 2) the Rudna-IX Shaft in Poland, a polymetallic mine. Kruszewski and others (2020) believe the “blue colouration is mainly provided by a yet unspecified Ni-, Co-, Mg-, and Mn-bearing Cu-Zn-Ca arsenate mineral close to parnauite , [a copper sulfate-arsenate].”

In looking at my micromount specimens from Tucson, I noticed effenbergerite (BaCuSi₄O₁₀) is a barium copper silicate of a nice blue color. As usual, my brain began to wander and wonder, and I assumed the blue was related to the copper content but was this silicate a particular or named shade of blue, like the ultramarine color of  juangodoyite.  So, I called up my alter ego, Guy Noir Private Eye, and decided to find an answer to one of life’s persistent questions—what color is effenbergerite? Boy, did I plunge off the 12^th floor of the Acme building into something bluer than the lakes of St. Paul, MN (apologies to Garrison Keilor).

It seems as effenbergerite is not only blue but is the natural occurrence of the color Han Blue! Now, I did not have the slightest idea what defined Han Blue, hence calling in Guy Noir. It turns out that Han Blue is officially “blue in color, perhaps the purest” of the total blue color spectrum. Han Blue, AKA Chinese Blue, is closely related to Han Purple, or Chinese Purple, as both are pigments containing barium, copper, silicon, and oxygen that were developed in China. Han Blue (BaCuSi₄O₁₀) is more chemically and thermally stable than Han Purple (BaCuSi₂O₆) and does not break down when subjected to dilute acids, and it becomes more bluish when ground while Han Purple becomes more purplish when ground (Berke, 2002).

If you have your own garage lab, and have a few common minerals and want to make some Han Blu pigments like the Han Destiny Chinese, then follow the recipe described by Berke and Wiedemann (2000): heat a mixture of either witherite (BaCO₃) or barite (BaSO₄), malachite (Cu₂(CO₃)(OH)₂₎ and quartz (SiO₂) in the presence of a lead salt (carbonate {cerussite} or oxide {litharge or massicot}). The lead salts serve as a catalyst for the chemical reaction and also facilitate the melting of the raw materials. Sounds great; however, most small-scale labs cannot create a temperature of 1000 degrees C needed for melting! Oh well, it sounded interesting. Berke (2007) explained the chemistry as: Cu₂(CO₃)(OH)₂ + 8 SiO₂ + 2 BaCO₃ → 2 BaCuSi₄O₁₀ + 3 CO₂ + H₂O. Besides the production of Han Blue, carbon dioxide and water vapor are released. I find it amazing that the Chinese alchemists or chemists were able to synthesize and develop (between 1200-200 BCE) Han Blue and Han Purple.  Perhaps the best-known use of the pigment was to decorate the well-known Terracotta Warriors.

Han Blue effenbergerite associated with clear quartz (I presume) from the Wessels Mine. Rob Lavinsky at irocks wrote (MinDat): any effenbergerite is good effenbergerite, considering how rare the species is, and how few specimens ever reach the market. Width of top photo ~1.0 cm. Bottom photo a closer view.

Silicates with only Ba and Cu as essential structural constituents are reltively rare in nature and only two such minerals have been documented thus far, including effenbergerite BaCuSi₄O₁₀ (Giester and Rieck, 1994) and scottyite BaCu₂Si₂O₇, and both originate from the same locality, [Wessels Mine in the Kalahri Manganese Field]. (Yang and others, 2013 ). Effenbergerite is a rather soft mineral (4+ Mohs), transparent to translucent, has a vitreous to resinous luster, a light blue streak and a brittle fracture.

The Wessels Mine, an underground operation, is located in the Kalahari Manganese Field, the world’s most prolific producer of manganese. The deposits are in the Hotazel Formation of Proterozoic age (Precambrian) and are the largest land-based (deep sea deposits are larger but nearly impossible to mine) sedimentary manganese deposits in the world, perhaps covering ~425 sq. miles. The ore has been subjected to both hydrothermal alteration (temperatures up to 450°C) and to metamorphism. The Wessels Mine, according to MinDat, is the home of 127 minerals including 18 Types.

The origin of the giant manganese deposits has been debated for many years but remain controversial: “Proposed models cover a diverse spectrum of genetic processes, from large-scale epigenetic replacement mechanisms, to submarine volcanogenic-exhalative activity, to purely chemical sedimentation whereby the influence of volcanism is of reduced significance” (Tsikos and Moore, 2006).

One of the more interesting facts about effenbergerite turned up by Guy Noir is that "effenbergerite has been synthesized and used in specialized studies for the electrochemical detection of the antibiotic ciprofloxacin. It acts as a sensitive modifier for electrodes, allowing for the precise quantification of ciprofloxacin in pharmaceutical products, natural water, and wastewater effluents" (Muungani and others, 2022).  Whoda thought.

I find it amazing that this rather rare and seemingly insignificant mineral can play a significant role in the biomedical field. What a wonderful piece of information I added to my personal knowledge field. I hope that info will last longer than my knowledge field of where I laid my car keys!

Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps learning stays young. The greatest thing in life is to keep your mind young.           Henry Ford

REFERENCES CITED

Berke, H., 2002, Chemistry in Ancient Times: The Development of Blue and Purple Pigments: Angewandte Chemie International Edition, vol. 41, no.14.

Berke, H. and H.G. Wiedemann, H. G., 2000, The Chemistry and Fabrication of the Anthropogenic Pigments Chinese Blue and Purple in Ancient China: East Asian Science, Technology, and Medicine. Vol. 17.

Giester, G., Rieck, B., 1994, Effenbergerite, BaCu[Si₄O₁₀], a new mineral from the Kalahari Manganese Field, South Africa: description and crystal structure. Mineralogical Magazine vol. 58 no.393.

Kruszewski, L. and others, 2020, Third Worldwide Occurrence of Juangodoyite, Na₂Cu(CO₃)₂, and Other Secondary Na, Cu, Mg, and Ca Minerals in the Fore-Sudetic Monocline (Lower Silesia, SW Poland): Minerals 2020, vol. 10, no. 2.

Siidra, Oleg I., and others, 2018, Saranchinaite, Na₂Cu(SO₄)₂, a new exhalative mineral from Tolbachik volcano, Kamchatka, Russia, and a product of the reversible dehydration of kröhnkite, Na₂Cu(SO₄)₂(H₂O)₂ : Mineralogical Magazine, vol. 82, no. 2.

Muungani, G., V. Moodley, and W.E. van Zyl, 2022:  Solid-state synthesis of the phyllosilicate Effenbergerite (BaCuSi₄O₁₀) for electrochemical sensing of ciprofloxacin antibiotic in pharmaceutical drug formulation. Journal of Applied Electrochemistry, vol. 52, no.2.

Tsikos, H. and J.M. Moore, 2006, The chemostratigraphy of a Paleoproterozoic MnF- BIF succession -the Voelwater Subgroup of the Transvaal Supergroup in Griqualand West, South Africa:  South African Journal of Geology, v. 109.

Wiedemann, H. G., Bayer, G. and Reller, A. 1998. Egyptian blue and Chinese blue. Production technologies and applications of two historically important blue pigments. In: S. Colinart and M. Menu (eds.) La couleur dans la peinture et l’émaillage de l’Égypte ancienne: Actes de la Table Ronde Ravello, 20–22 mars 1997. Bari: Edipuglia, 195–203.

Yang, H., Downs, R. T., Evans, S. H., Pinch, W. W., 2013, Scottyite, the natural analog of synthetic BaCu₂Si₂O₇, a new mineral from the Wessels mine, Kalahari Manganese Fields, South Africa. American Mineralogist, vol. 98, no. 2.

HOWLING AND CELEBRATING TUCSON 2026

 

Just howlin’ at the moon celebrating Tucson 2026.

There really is not a good way to describe the Tucson Gem and Mineral Show (the official show) except to say mind boggling and overpowering.

A view of the main floor of the Convention Center from the second floor Micromount Playroom.

My best estimate is that well over 300 vendor and display “booths” were created and occupied, most on the main floor and a large side room. The vendors had the traditional tables and display cases while the displays were set up in the types of cases one sees at most mineral shows. The major difference is that many of the cases are large (longer) than most traditional show cases. The displays were created by a multitude of rock and mineral clubs, companies, and individuals. There are a number of “Best XXX Awards” given out each year and cases often try to display minerals that correspond to the yearly theme, the 2026 Red, White & Blue—A Celebratory & Patriotic Feast.

The Tucson Show is held during the second week of February, Thursday through Sunday, at the Tucson Convention Center, a large building in the center of downtown. Ten-dollar parking has gone by the wayside and has jumped to $15. Unfortunately, “payment to the parking attendant in the booth” has also disappeared and a much longer and more complicated smart phone system is now in place.  Admission to the show is $15 with discounts for children and seniors (one day only). Several “gem show shuttles” operate an established schedule haul participants from outlying venues and motels to the Center.

The organization Friends of Mineralogy hosts a symposium on Saturday and Sunday mornings with a variety of presentations including:

·       John Stuart McCloy, Cuprorivaite: Egyptian Blue, humanity’s first inorganic pigment.

·       Johan Maertens, Heaven and Hell in Ohio [about Celestine].

·       Donald A. Dallaire, New Hampshire’s Red, White & Blue Minerals.

·       John Rakovan, Pleochroism in minerals.

·       Markus Raschke, An ocean within – new insights into structure and phases of water in minerals.

·       Bruce Kelley, Finding Art in Minerals: How an interest in color and form ignited my passion for minerals.

·       John Stuart McCloy, Cuprorivaite: Egyptian Blue, humanity's first inorganic pigment.

·       Johan Maertens, Heaven and Hell in Ohio [about Celestine.

·       Donald Dallaire, New Hampshire's Red, White & Blue Minerals,

·       John Rakovan, Pleochroism in Minerals.

·       Markus Raschke, An Ocean Within – New Insights into Water in Minerals.

The Author Roe Memorial Micromount Symposium was held on Friday morning with the following three presentations:

·       Museums, Minerals and Micromounts by Nadine Gabriel (via Zoom from Mineralogy at the Natural History Museum, London).

·       Minerals of the Chilean Mineralogical Expedition, Sam Gordon and the Academy of Natural Sciences of Philadelphia by Patrick E. Haynes.

Type Mineralogy of Oregon: History, Revisions, and Puzzles by Julian C. Gray.

·      

After the Symposium micromounters flocked back to the playroom to swap and identify micros.

This great display with red, white and blue minerals was put together by members of the Young Mineral Collectors.

 

 

 

Each year I am fascinated by the displays of native silver, most of which comes from the mines at Kongsberg, Norway) producing for 350+ years).

As for colored crystals it is easy for me to pick this beryl variety aquamarine from Goand Mine, Skardu, Pakistan.

What a thrill for an ole paleontologist to hoist a mammoth tusk (Alaska).

And I leave you with two contrasting photos: Mexican Poppies from my temp home in Tucson, and my back yard in Wisconsin.