Group of cube octahedral pyrite crystals forming a very aesthetic and brilliant aggregate.

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Group of pyrite crystals that show well defined faces of the cube and the octahedron. Very well defined faces and edges, showing triglyphic striations on the faces of the cube and not on the octahedron, as is to be expected. With an exceptional luster. It is accompanied by quartz crystals.

Group of pyrite crystals with cube and dodecahedron faces, with diploid forms, striated faces, certainly complex crystallography, which adds interest to the specimen. Crystals are interpenetrated. The brightness is exceptional, difficult to photograph. It is accompanied by quartz crystals.

This specimen was purchased at the Expominer fair (Barcelona) in 1985 from a dealer who brought Peruvian material. It was labeled as "enargite" from Huancavelica, a Peruvian mining region well known among mineral collectors. The specimen shows numerous crystals with a metallic luster, isolated or in groups, on a sulfide matrix (mainly pyrite). By observing them carefully and using a magnifying glass, we were able to see different crystalline forms that indicated the presence of various species. We proceeded to extract some crystals to study them.
SEM-EDS analysis indicated that elongated prismatic crystals with polysynthetic growths on the faces and hopper shapes (perimorphosis?) were a copper sulfoantimonide, with some bismuth and arsenic. This composition and its percentages correspond to chalcostibite, and the Bi would indicate the series with emplectite. Chalcostibite was confirmed by X-ray diffraction (XRD). An unusual species and less so for this Peruvian mine.
Other crystals showed prisms with faces striated and truncated by the pinacoid. Their analysis indicated that it was a copper-lead sulfoantimonide, with traces of Bi, consistent with twinned bournonite, a species also confirmed by XRD.
On the matrix we observe crystals with tetrahedron shapes, sometimes flattened. XRD indicated the presence of tetrahedrite. SEM-EDS analysis of small crystals associated with chalcostibite indicated that it could be tetrahedrite-(Zn), with possible argentotetrahedrite-(Zn). We will send labels and all the analysis reports to the buyer.

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Rich group of quartz crystals, translucent to hyaline, and with the terminal faces of the rhombohedron different from the usual ones. Among them, a very good size doubly terminated crystal stands out, well defined and with the faces of the prism with striations perpendicular to the main axis. They are disposed on a matrix with quartz and sphalerite crystals.

These specimens of Peruvian arsenopyrite stand out for their excellent luster and perfection of its crystals. With the camera I am not able to capture its real beauty. On a sulfide matrix we can enjoy hundreds of arsenopyrite crystals, prismatic, with defined terminal faces, rather than well-defined. They're accompanied by chalcopyrite crystals with dull luster, but gold tone, also well-defined and twinned. Brilliance and quality. Good sized specimen.

These specimens of Peruvian arsenopyrite stand out for their excellent luster and perfection of its crystals. With the camera I am not able to capture its real beauty. On a sulfide matrix we can enjoy hundreds of arsenopyrite crystals, prismatic, with defined terminal faces, rather than well-defined. They're accompanied by chalcopyrite crystals with luster and gold color, also well-defined and twinned. Brilliance and quality.

Very esthetic miniature formed by a group of quartz crystals covered by beveled cubic pyrite on which various tabular crystals of hübnerite stand out, well defined and with a very visible red transparence. Specimen from the Joan Astor collection, acquired in 1982 from Bailey Minerals (Ángel Jesús Talabán García, Segovia 1942-Madrid 2007).

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Druse of pyrite crystals with faces of the cube and rhobododecahedron, striated faces, complex crystallography, which adds interest to the specimen. Back side is curiously flat. The luster is exceptional, not easy to take photos. The crystals are interpenetrated. A classic from the mine from which the bases for the FIFA football award "Ballon d'Or" are obtained...

Group of chalcopyrite crystals, bright, interpenetrated, with well defined edges. On the faces of the crystals we can see small aggregates of crystals, probably tetrahedrite. They are accompanied by sphalerite crystals on matrix. An old piece, from the time of those that are preserved in the Freiberg Mining School Museum.

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Group of cyclically twinned bournonite crystals, with a metallic gray color, interpenetrating each other. They are disposed on a matrix of very brilliant octahedral pyrite, partially covered by complex sphalerite crystals.

Group of octahedral pyrite crystals, very brilliant and well defined, which are accompanied by complex crystals of sphalerite. On them we observed numerous white globular crandallite aggregates (analyzed by XRD). This combination of minerals is unusual in the deposit, with this phosphate being the first citation.

Group of octahedral pyrite crystals, very brilliant and well defined, which are accompanied by complex crystals of sphalerite. On them we observed numerous white globular crandallite aggregates (analyzed by XRD). This combination of minerals is unusual in the deposit, with this phosphate being the first citation.

Druse of pyrite crystals with faces of the cube and rhobododecahedron, with diploid forms, striated faces, complex crystallography, which adds interest to the specimen. The luster is exceptional, not easy to take photos. The crystals are interpenetrated. A classic from the mine from which the bases for the FIFA football award "Ballon d'Or" are obtained...

Good size and rich aggregate of andradite-grosularia crystals with an intense brown color on the surface, but with color zoning, clearer inside. The exterior of the sample shows a dark reddish-brown tone with very well defined trapezohedral crystals, but inside the crystals have a very aesthetic golden tone. Multi-layered bands ranging from reddish brown to green to gold are shown in the fracture zones of the piece. For this reason we prefer to label it as the andradite-grossular series.

Very aesthetic specimen that shows two generations of orpiment. One with an intense orange color, formed by numerous brilliant crystals. A second generation formed by crystals that cover the arsenopyrite-pyrite matrix, with a darker tone. A different sample from this classic Peruvian mine.

In this specimen we can observe brilliant aggregates of brown transparent römerite crystals, a very rare iron sulphate. They are accompanied by coquimbite showing an intense violet color under fluorescent light or LED type. They're accompanied by yellow metavoltine/copiapite crystals, along with minor fibrous halotrichite. Note that under the magnifying glass we can navigate in a world of brilliant crystals, some of which of krausite species (yellowish to grey transparent). We left this identification pleasure to the collector. Regarding its environmental stability, this sample has been stored during more than eight years without further alteration.

Epidote crystal, dark olive green in colour, very bright, with defined terminations, striking lighter green reflections and many flashes of greenish-yellow internal fire. Excellent specimen of Peruvian epidote.

Good size epidote crystal, dark olive green in colour, very bright, with defined terminations, striking lighter green reflections and many flashes of greenish-yellow internal fire. Excellent specimen of Peruvian epidote.

On a rich group of rosettes of rhodochrosite, with a pinkish tone and a silky luster, there are various crystals of tetrahedrite, defined, brilliant and contrasting on the matrix.

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Groups of aggregates of rhodochrosite crystals, of a delicate pink color, brilliant. They are accompanied by colorless aggregates of small quartz crystals. Very aesthetic.

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Group of rhodochrosite crystals with a uniform pink color, with well-defined rhombohedron echeloned and scalenohedron forms. Good gemmy transparence. They are accompanied by other smaller rhodo crystals. On a solid matrix with quartz crystals with inclusions and manganese oxides.

Group of rhodochrosite crystals with a uniform pink color, with well-defined rhombohedron echeloned and scalenohedron forms. Good gemmy transparence. They are accompanied by other smaller rhodo crystals. On a solid matrix with quartz crystals with inclusions and manganese oxides.

An old specimen of this Peruvian mine that shows a large group of cubic galena crystals, interpenetrated, with its characteristic gray tone. They have stepped growths on the faces and some natural cavities, which give them a differentiated appearance.

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Group of chalcopyrite crystals, one of good size, with defined shapes arranged on quartz hyaline crystals. An aesthetic miniature.

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