Bright silvery to bronze aggregate of allargentum (upper left corner) on matrix. Two sides of the matrix are covered with minute safflorite crystals. The allargentum has pseudocrystalline habit.
Shaft 371 is the main shaft of the former Aue Mining Company (formerly Object 09) of SDAG Wismut, a uranium mine in the Westerzgebirge. With a total depth of more than 1,800 m, the mine was the deepest mine in Germany until its closure (mindat). These type of specimens, although they are not "aesthetic", have an essential systematic and historical interest. For lovers of "gray minerals", like myself...

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Malachite specimens from this Upper Katanga mine are notable for radial aggregates of fine crystals that, taken together, have a velvety appearance and excellent brilliance. Intense green colour, good size and fine aesthetics.

Very esthetic specimen of calcite formed by various flattened interpenetrated rhombohedral crystals, almost lenticular, with very well defined and striated faces. Between translucent to transparent, shiny and on a rocky matrix. It exhibits intense pink to red fluorescence under UV-LW light. Good size and quality.

190 €

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White elongated crystals of pearly luster in parallel growths implanted on groups of crystals of malachite with a silky luster and a very deep and uniform color. From a find ca. 2010 in Bou Beker where this association had not been found before.

Calcite specimens from la Florida mines are known and valued worldwide. Noted for their complex twinned crystals on a prevalent rhombohedra forms, over scalenohedra. In this sample we offer, we have extraordinary crystals in which the predominance of twinned rhombohedrons is very clear and visible. Transparence is excellent, with defined striated faces and edges, undamaged and a visible twin. It has a delicate yellowish tone. It is cleanly implemented on a matrix of dolomite and calcite. A gem of Cantabria, always surprising the collectors for its aesthetics.

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Excellent specimen of Asturian fluorite, from the classic Berbes area, formed by a dolomitic matrix with tabular book-shaped baryte crystals, partially coated with quartz and fluorite crystals. Fluorite crystals present very defined cubic shapes, with transparence, brilliance and a uniform purple to violet color. Very aesthetic specimen from thsi classic Spanish locality.

320 €

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Good-sized specimen covered with numerous cubic to prismatic fluorite crystals, transparent, brilliant and with aesthetic colour zoning. It has slightly beveled edges. A fine quality specimen from this classic Asturian locality, the specimens of which are highly appreciated by collectors.

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Polished section of an iron-manganese nodule. We can perfectly observe the polymetallic concentric growths. This rare and historical specimen comes, according to the label that accompanies it, from surveys carried out at a Soviet base located in the Indian Ocean (southeast area), in a trench called "naturalis" about 5000 m deep. Due to the consolidating treatment of the piece and these data, we can say that it is an old specimen from perhaps the middle of the s. XX. The best-known nodules come from North American investigations in the Clarion-Clipperton area, in the Pacific Ocean, to the west of the USA, or those off the coast of Peru. Interesting as a source of Mn, Co, Ni, Cu... Very rare to find on the market.

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Enstatite, variety bronzite. This specimen shows a group of intergrown crystals of bronzite, with the characteristic brassy-golden iridescence when viewed at varying angles. The effect is related to what we can see in labradorite, this specimen has a lively golden "labradorescence". A member of the orthopyroxene subgroup.

Rich group of orange lenticular crystals of schwartzembergite, analyzed by SEM-EDS, accompanied by seeligerite, of a light yellow color. Both are rare lead cloroiodates. It is one of the several specimens those remembered Dr. Joan Viñals (1951-2013) brought and studied from his trip to Chile in first years of 2000's. With the E. Kucera (Barcelona) label.

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White to bluish globular aggregates of arsenocrandallite, accompanied by brown yukonite. These specimens were the first that Joan Viñals analyzed from this classic Murcian mine and that would lead to the discovery of the barahonaite (Al and Fe). With handwritten label.

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Rich group of small pyromorphite crystals, prismatic, hexagonal and truncated by pinacoidal faces. Good color and shine. Examples of this mine are not easy to come by today. The sample is accompanied by the handwritten label of Joan Viñals.

65 €

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Monazite-(Ce) crystal, floater, rich in faces, with luster and intense brown color. Nowadays finding specimens with this quality is not easy.
These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.

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Very good monazite-(Ce) crystal, floater, rich in faces, with luster and light brown color. It is accompanied by a cubic crystal of columbite-tantalite embeded in. These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.

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Excellent monazite-(Ce) crystal, totally floater, rich in faces, with luster and intense brown color. Nowadays finding specimens with this quality is not easy.
These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.

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Group of strontianite crystals disposed on the rocky matrix. Joan Viñals's label indicates Bédar bridge, which could be the zone of the mining train bridge. It is accompanied by the handwritten label.

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Groups of very well defined chalcocite crystals, with hexagonal pyramidal shapes, with striated faces perpendicular to the main axis and forming aggregates. Metallic gray luster with bluish iridescences. They are disposed on a matrix with brilliant quartz microcrystals. A classic from Kazakhstan, each day scarcer.

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Yellowish-green aggregates of beaverite-(Cu), accompanied by globular groups of green osarizawaite crystals. From this classic Spanish mine.

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This is a really good crystal cluster of bismuthinite from the Mina Tazna in Bolivia. It is formed by large, terminated, prismatic crystals of bismuthinite, divergent, gray metallic. Some crystals show a metallic patina from a thin coating of marcasite/pyrite. On the back side some quartz crystals and gray-white uncovered metallic natural bismuthinite crystals. The Tazna Mine is a historic bismuth-tungsten mine in the high Andes of Bolivia that has produced noteworthy specimens for decades. Samples with this quality are very rare seen on the market. Specially for connoisseur "gray" mineral collectors...

280 €

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This specimen shows numerous intense red-orange crystals of crocoite accented by yellow-green microcrystals of vauquelinite. The combination of intensely colorful species made this specimen very aesthetic. It show jack-straw aggregates formed by elongated chisel shaped crystals. Few samples are seen on the market. A rare, and important, display-quality German classic from J. Viñals and E. Nicolau collection.

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This specimen from the Broken Hill mine has an incredibly rich coating of the lead oxyde mineral: minium. Both sides are coated with this intense, reddish-orange lead oxide. Minium is pseudomorph after cerussite crystals. Highly representative of the species and the locality. With the handwritten label from Ausrox.

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Autunite specimens, which transform into meta-autunite by losing naturally water molecules, from this Portuguese mine are among the most aesthetically pleasing in the world due to their intense yellow-greenish colour, transparence, and luster. In this specimen we can observe numerous aggregates of tabular crystals, some isolated and contrasting on the stalactitic matrix. SEM-EDS analyzes have been carried out confirming the presence of Mg, but in a very small amount. Fluorescence under LW-UV light is exceptional.

If the autunite (meta-autunite) specimens from this Portuguese mine are among the most aesthetic in the world due to their intense greenish-yellow colour, transparency and brilliance, they also stand out for being sometimes accompanied by another even more interesting species: phurcalite. It is also a hydrated calcium phosphate like autunite, but with a different structure and belonging to the phosphuranylite group (autunite is part of the autunite group).
In the analysis we have carried out by SEM-EDS (photo attached) the presence of the two phosphates becomes evident: the autunite as tabular crystals, while phurcalite appears as elongated prisms with defined terminal faces, which without magnification resemble needles. Apart from the appearance of the crystals, autunite usually has an intense greenish-yellow color and phurcalite is slightly orange-yellow. Also indicate that phurcalite does not usually fluoresce, while autunite is highly fluorescent. As we have indicated, sometimes the phurcalite is associated with autunite, so the fluorescence we see is that of the autunite. We will send analytical results to the buyer.

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Autunite specimens, which transform into meta-autunite by losing naturally water molecules, from this Portuguese mine are among the most aesthetically pleasing in the world due to their intense yellow-greenish colour, transparence, and luster. In this specimen we can observe numerous aggregates of tabular crystals on matrix. SEM-EDS analyzes have been carried out confirming the presence of Mg, but in a very small amount. Fluorescence under LW-UV light is exceptional.

If the autunite (meta-autunite) specimens from this Portuguese mine are among the most aesthetic in the world due to their intense greenish-yellow colour, transparency and brilliance, they also stand out for being sometimes accompanied by another even more interesting species: phurcalite. It is also a hydrated calcium phosphate like autunite, but with a different structure and belonging to the phosphuranylite group (autunite is part of the autunite group).
In the analysis we have carried out by SEM-EDS (photo attached) the presence of the two phosphates becomes evident: the autunite as tabular crystals, while phurcalite appears as elongated prisms with defined terminal faces, which without magnification resemble needles. Apart from the appearance of the crystals, autunite usually has an intense greenish-yellow color and phurcalite is slightly orange-yellow. Also indicate that phurcalite does not usually fluoresce, while autunite is highly fluorescent. As we have indicated, sometimes the phurcalite is associated with autunite, so the fluorescence we see is that of the autunite. We will send analytical results to the buyer.

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