Uraninite partially coated with gummite; we can see the inner part of the black uraninite and the gummite surrounding it. The faces of the cube are also clearly visible. Gummite is a yellow amorphous mixture of uranium minerals, oxides, silicates, and hydrates of uranium, derived from the alteration of uraninite. It is named for its gum-like luster. 

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Euxenite-(Y) is an uncommon oxyde of niobium with tantalum and titanium and Rare Earth Elements (REE), with some calcium and radioactive elements like uranium or thorium. These elements give it a radioactive activity. This specimen we offer you is a cluster of parallel growth crystals, well-formed, with a chisel termination.With the classic ocher patina. A good chance to get a fine and good sized specimen.

360 €

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Druse of tabular torbernite crystals from this classic mine for the species. Good luster, translucent to traansparent, and with a very intense green color.

Druse of dioptase crystals, with very defined faces and edges, brilliant, transparent, and disposed on a quartz rocky matrix. The color is very distinctive, difficult to reproduce in photography. They are accompanied by small aggregates of malachite crystals, with a different green. A piece of good size and quality.

400 €

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A group of cubic fluorite crystals, ranging in color from purple to violet depending on the incident light. Well-defined faces and edges, luster, and transparency. On the back, they are partially covered with quartz microcrystals.

Specimen formed by a druse of quartz microcrystals on which several groups of cubic fluorite crystals have grown. They have faces that are asymmetrically beveled by the dodecahedron. Its transparency allows us to see a curious geometric zoning of color. The specimen comes from the J. Vilalta collection and the A. Soliveres collection. From a mine from which it is difficult to find pieces.

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A novelty from Sainte-Marie-aux-Mines 2022. These specimens come from a recent find in this mining area of the Black Forest and are reminiscent of those found decades ago in this area. They show radial aggregates of extremely brilliant pyrolusite crystals that partially replace manganite. By X-ray diffraction we have been determined the presence of both species, even with a certain predominance of manganite. They usually appear on a matrix of pink granite or as groups of large crystals in parallel growth. In the specimens we can observe the inclined flattened terminal faces. They are highly aesthetic pieces those will become part of the best specimens of these species for European mineralogy. We will send the XRD to the buyer.

470 €

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Druse of prismatic acicular pyromorphite crystals, transparent, shiny and with the characteristic green color. They are arranged on a quartz matrix. A very aesthetic piece from the Nicolau collection (Barcelona) and with a Joan Viñals label.

140 €

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Group of twinned prismatic scolecite crystals, very brilliant and transparent. It is accompanied by small hyaline crystals of fluorapophyllite-(K), bright and very defined. Scolecite is a rather rare species of the zeolite group from India. With handwritten label by J. Viñals and belonged to the Nicolau collection (Barcelona).

190 €

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Botryoidal aggregates of smithsonite with a very tastefull bluish green colour, translucent and with brilliance. They are disposed on matrix. From a very interesting American locality. It fluoresces intensely under LW-UV light.