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).
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.
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.
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 20th 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.
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 12th 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.
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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.
