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Parallel growth of hübnerite crystals, of very good size, with evident reddish reflections. With defined terminal faces, translucent on edges and with brilliance. With hyaline quartz crystals. Excellent old piece from this Peruvian mine.
Scalenohedral rhodo crystals with a whitish patina. They are accompanied by very brilliant hyaline quartz crystals.
Group of geocronite-jordanite crystals, with striated pseudohexagonal shapes. They have a lighter gray sheen than the galena with which they are often associated. The analyzes show a correlation between geocronite-jordanite, both are isostructural and form series. The crystals analyzed (both these that we present and others) show that the composition moves in the intermediate zone of the series. Therefore, the correct thing would be to label these specimens as geocronite-jordanite, avoiding saying that they are only geochronite. We will send all analyzes to the buyer.
The geocronite-jordanite crystals are accompanied by crystals of sphalerite, of galena, associated with transparent crystals of green fluorite, both cubo-octahedral, the latter truncated by the faces of the cube and the trapezohedron.
Group of geocronite-jordanite crystals, with striated pseudohexagonal forms. They have a lighter gray luster than the galena with which they are often associated. The analyzes show a correlation between geochronite-jordanite, both are isostructural and form series. The crystals analyzed (both these that we present and others) show that the composition is in the intermediate zone of the series. Therefore, the correct way is to label these specimens as geocronite-jordanite, avoiding saying that they are only geochronite. We will send all analytical reports to the buyer.
The geocronite-jordanite crystals are found on a matrix formed by complex sphalerite crystals, almost black in color, associated with transparent green fluorite crystals, octahedral cubes, truncated by the cube and trapezohedron faces.
Group of interpenetrated pyrite crystals with an exceptional luster. This specimen stands out for its complex crystallography, with cube shapes, triglyphic striations, and vertices rich in probably trapezohedral faces. A piece to enjoy in its study, the kind that I like...
Group of cube octahedral pyrite crystals forming a very aesthetic and brilliant aggregate.
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.
Rich group of octahedral pyrite crystals, with an exceptional luster. A good-sized, very aesthetic specimen, from this classic Peruvian mine.
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.
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).
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...
Numerous well-defined and interpenetrated sphalerite crystals are arranged on a matrix with quartz crystals, accompanied by pyrite crystals. In the upper part, a group of chalcopyrite crystals with some indentation, which allows us to see the color and brilliance.
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.
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.