Quartz specimens from this Colombian mine, located in the Boyacá emerald mining area, have been well known since the end of the last century. By 2017, new galleries were opened those located different geodes. These crystals, called "mango quartz" or "crown quartz" were found in them, with inclusions that, after being recently analyzed, were determined as halloysite. The inclusions show filamentous structures and the tips of the crystals turn to orange tones. On our website we have already sold some samples with these inclusions on sale, without the orange coloration. Really aesthetic and on a matrix with goethitized dolomite-siderite.

Quartz specimens from this Colombian mine, located in the Boyacá emerald mining area, have been well known since the end of the last century. By 2017, new galleries were opened those located different geodes. These crystals, called "mango quartz" or "crown quartz" were found in them, with inclusions that, after being recently analyzed, were determined as halloysite. The inclusions show filamentous structures and the tips of the crystals turn to orange tones. On our website we have already sold some samples with these inclusions on sale, without the orange coloration. Really aesthetic and on a matrix with goethitized dolomite-siderite.

Quartz specimens from this Colombian mine, located in the Boyacá emerald mining area, have been well known since the end of the last century. By 2017, new galleries were opened those located different geodes. These crystals, called "mango quartz" or "crown quartz" were found in them, with inclusions that, after being recently analyzed, were determined as halloysite. The inclusions show filamentous structures and the tips of the crystals turn to orange tones. On our website we have already sold some samples with these inclusions on sale, without the orange coloration. Really aesthetic and on a matrix with goethitized dolomite-siderite.

Goethite specimen from this classic French mine, now closed and partially restored, which shows druses of goethite small crystals, defined and very, very bright. Under loupe is incredible. The sparkles of the crystals in the light are spectacular. The specimen was analyzed by Raman spectroscopy to confirm the species.

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Quartz specimen with groups of crystallized gold. It is accompanied by galena and grey cosalite needles (a bismuth and lead sulfosalt). A gold curiosity of this French mine that was precisely exploited by the "Société des Mines du Bourneix" for the extraction of gold.

Specimen formed by several interpenetrating davidite-(La) crystals. We can observe various curved, shiny facets of this rare species, from the crichtonite group, and of a complex formula with an unique combination of elements:  La(Y,U)Fe₂(Ti,Fe,Cr,V)₁₈(O,OH,F)₃₈.
It belongs from the type locality for the species: Radium Hill. To confirm the species we have carried out SEM-EDS analysis with results consistent with expectated. It is not easy to find specimens of the type locality and less with facets.

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Specimen formed by several interpenetrating davidite-(La) crystals. We can observe various curved, shiny facets of this rare species, from the crichtonite group, and of a complex formula with an unique combination of elements:  La(Y,U)Fe₂(Ti,Fe,Cr,V)₁₈(O,OH,F)₃₈.
It belongs from the type locality for the species: Radium Hill. To confirm the species we have carried out SEM-EDS analysis with results consistent with expectated. It is not easy to find specimens of the type locality and less with facets.

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Goethite specimen from this classic French mine, now closed and partially restored, which shows druses of goethite small crystals, defined and very, very bright. Under loupe is incredible. The sparkles of the crystals in the light are spectacular. The specimen was analyzed by Raman spectroscopy to confirm the species.

Sold

Quartz specimens from this Colombian mine, located in the Boyacá emerald mining area, have been well known since the end of the last century. By 2017, new galleries were opened those located different geodes. These crystals, called "mango quartz" or "crown quartz" were found in them, with inclusions that, after being recently analyzed, were determined as halloysite. The inclusions show filamentous structures and the tips of the crystals turn to orange tones. On our website we have already sold some samples with these inclusions on sale, without the orange coloration. Really aesthetic and on a matrix with goethitized dolomite-siderite.

Brilliant specimen formed by a druse of defined tarpezohedral crystals of grossular, hessonite variety. Intense color, shine and transparence. It is accompanied by groups of green clinochlorine crystals.

Elongated cubic fluorite crystal of very good size, with tile growths on the faces. Between translucent to transparent and with a very uniform violet color. It is complete on both sides and is placed on a small matrix with quartz.

Very interesting specimen of elbaite that has been partially transformed into lepidolite. A Brazilian curiosity. It comes from the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

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Group of hyaline quartz crystals, one of them predominant, with excellent transparence, brilliance and sharpness. They come from this Aragonese locality known for its aesthetic quartz specimens, difficult to see with quality today. It comes from the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

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Very bright corundum crystal, var. ruby, very well defined and pink to brown in color. It comes from the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

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Classic ruby specimen, cherry to pink in color, embedded in a matrix of zoisite and micas. It comes from the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

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Very brilliant pyrohedron cluster, of good size and with well defined faces and edges. With some hematite brilliant lamellar crystals. From this classic Italian locality. It belongs to the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

Very brilliant pyrohedron cluster, of good size and with well defined faces and edges. From this classic Italian locality. It belongs to the Joan Astor collection (Barcelona), with a handwritten and typewritten label.

55 € 38 €

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On a microcline-orthoclase-quartz matrix, several laminar aggregates of autunite are disposed, yellow color, transparent to translucent and brilliant. They present, as usual, intense fluorescence under UV light. It belongs to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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Very aesthetic specimen from this classic Italian mine. Several magnetite crystals with dodecahedron forms, some of them very interestingly distorted crystalography, with intense luster and very well defined. It is accompanied by octahedral pyrite crystals. It comes from the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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The label of this sample indicates that it is a specimen from Reocín. The matrix is a dolomite, different from the usual matrix of Udías hydrozincite specimens, which is usually limonite. In addition, the piece was acquired from Enric Kucera, who is usually quite precise in the labeling. It comes from the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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Andradite var. melanite (Ti-rich) from this well-known skarn deposit. Sharp, lustrous, black and brown dodecahedrons. From the former Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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Druse of fluorapophyllite-(K) crystals covering aggregates of kinoite crystals with an intense blue color. A sample from the past, belonging to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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Old specimen of a good size formed by a matrix partially covered by small but brilliant crystals of duftite, a lead and copper arsenate, with a deep green color. They are accompanied by prismatic crystals of mimetite, between white and yellowish, together with crystals of cerussite. An entertainment under the magnifying glass. It comes from the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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A brilliant specimen of epidote, brilliant, transparent, richly faceted crystals with a very aesthetic olive green color. With some diopside crystals. The beauty of these specimens is incomparable for the species. It comes from the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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Green aggregates of lindgrenite, forming shiny crusts. Some corroded crystals are observed, associated with bright molybdenite. It belongs to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

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