This specimen shows a group of twinned cubanite crystals. They exhibit excellent luster, iridescence, twin faces and striations, and is complete. The rarity of this material makes it highly desirable for collectors. It comes from the classic Canadian locality for this species.

This specimen shows a group of twinned cubanite crystals. They exhibit excellent luster, with visible faces and some natural fractures, but the rarity of this material makes it highly desirable for collectors. It belongs from the classic Canadian locality for the species.

An exceptional specimen of muscovite composed of numerous aggregates of hexagonal crystals of this member of the mica group. Its yellowish-green color is very distinctive. Specimens of this type are rare, especially at this size. It is accompanied by albite, specifically the clevelandite variety.

This specimen consists of numerous veins of violet-colored stichtite, accompanied by veins of serpentine. Stichtite is a rare hydrated magnesium and chromium carbonate. The species is named after Robert Carl Sticht, the renowned American copper metallurgist and mine manager. At Kaapschehoop, stichtite occurs as irregular to rounded masses or as veinlets, generally less than 1 mm wide, within the serpentine.

Specimen of beryl aquamarine variety. Very transparent, delicate bluish color to colorless, with developed prism faces and with terminal faces of the dipyramid truncated by the pinacoid. With rutile inclusions. On a doubly terminated quartz crystal. A gemmy miniature.

This is a brilliant and esthetic cobaltite specimen that shows a sharp and brilliant crystal, with dominant forms of the cube and pyritohedron, included in the massive pyrrhotite matrix. Håkansboda is an old mine, opened in the 17th century and worked until 1873, with only minor mining during World War I. An European classic mine and specimen.

An excellent specimen of fluorapatite, formed by the parallel growth of two crystals, with very defined hexagonal shapes, an intense green color, and exceptional luster. From this Canadian locality, a classic location for the species.

A striking specimen composed of numerous prismatic, highly faceted cassiterite crystals with exceptional luster and translucency, displaying a honeyed hue. This is an excellent old specimen from the little-known Seal Hole mine in Cornwall. A very showy and uncommon specimen in this mine.

Marialite crystal, spodumene group, slightly greenish-yellow, with parallel growths and well-defined terminal faces. Transparent to translucent, with some very transparent areas. A gem from the Trigo collection, from Mataró, with a handwritten label.

Kunzite crystal, with striated faces, with good color and transparence. A gemmy specimen with handwritten label.

These specimens show yellowish nodules included in a feldspar matrix. First SEM-EDS analysis have yielded a phosphate of Th and Ca, with minor Pb. XRD has shown patterns of "bravantite", the old name for cheralite and brockite. The chemical base formula for these species are: grayite (Th,Pb,Ca)(PO₄)·H₂O; cheralite CaTh(PO₄)₂; brockite (Ca,Th,Ce)(PO₄)·H₂O. REE has not been found in EDS. We could say that this yellow nodules belongs from altered monazite, formed by mixed species cheralite-grayite, with minor brockite. Accompanied in matrix by meta-autunite and fluorite.

Reserved

These specimens show yellowish nodules included in a feldspar matrix. First SEM-EDS analysis have yielded a phosphate of Th and Ca, with minor Pb. XRD has shown patterns of "bravantite", the old name for cheralite and brockite. The chemical base formula for these species are: grayite (Th,Pb,Ca)(PO₄)·H₂O; cheralite CaTh(PO₄)₂; brockite (Ca,Th,Ce)(PO₄)·H₂O. REE has not been found in EDS. We could say that this yellow nodules belongs from altered monazite, formed by mixed species cheralite-grayite, with minor brockite. Accompanied in matrix by meta-autunite and fluorite.

45 €

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These specimens show yellowish nodules included in a feldspar matrix. First SEM-EDS analysis have yielded a phosphate of Th and Ca, with minor Pb. XRD has shown patterns of "bravantite", the old name for cheralite and brockite. The chemical base formula for these species are: grayite (Th,Pb,Ca)(PO₄)·H₂O; cheralite CaTh(PO₄)₂; brockite (Ca,Th,Ce)(PO₄)·H₂O. REE has not been found in EDS. We could say that this yellow nodules belongs from altered monazite, formed by mixed species cheralite-grayite, with minor brockite. Accompanied in matrix by meta-autunite and fluorite.

Reserved

These specimens show yellowish nodules included in a feldspar matrix. First SEM-EDS analysis have yielded a phosphate of Th and Ca, with minor Pb. XRD has shown patterns of "bravantite", the old name for cheralite and brockite. The chemical base formula for these species are: grayite (Th,Pb,Ca)(PO₄)·H₂O; cheralite CaTh(PO₄)₂; brockite (Ca,Th,Ce)(PO₄)·H₂O. REE has not been found in EDS. We could say that this yellow nodules belongs from altered monazite, formed by mixed species cheralite-grayite, with minor brockite. Accompanied in matrix by meta-autunite and fluorite.

55 €

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An excellent specimen formed by numerous epidote crystals, from the classic locality of Casterner. Fan-shaped crystals, they are very bright and with an excellent transparence. Samples of this area are already few. It is currently forbiden to collect in the area.

An excellent specimen formed by numerous epidote crystals, from the classic locality of Casterner. Fan-shaped crystals, they are very bright and with an excellent transparence. Samples of this quality are already few. It is currently forbiden to collect in the area.

In this specimen, we can see pyroxmangite, pink in color, accompanied by black veins of todorokite and by tephroite, which appears as more brownish patches. I have conducted studies on similar specimens that showed a predominance of pyroxmangite over rhodonite, which also occurs in this mine and is more massive; often they appear mixed.

This sample belongs from an old mining operation that we generically call the Serrana mine, although in fact it consists of two separate workings, with two distinct spoil heaps: one corresponding to the Serrana mine proper (with horizontal workings), and the other (closer to the river, with vertical workings) known as the Manganès mine. Right next to the mine, there is an interesting winery that takes advantage of one of the mines as a wine cellar.

50 €

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Blocky aerinite criptocristalline with fragments of dolerite included. Excellent color. Aerinite was used as a blue pigment in many Romanesque paintings in the Pyrenees between the 11th and 14th centuries. Its characteristic blue color varies from dark to pale blue. In fact, its name comes from a Greek root aerinos meaning "atmosphere" or "sky", as it was only known by that color. Obtaining these specimens of pure aerinite nowadays is almost impossible.

Blocky aerinite criptocristalline with fragments of dolerite included. Excellent color. Aerinite was used as a blue pigment in many Romanesque paintings in the Pyrenees between the 11th and 14th centuries. Its characteristic blue color varies from dark to pale blue. In fact, its name comes from a Greek root aerinos meaning "atmosphere" or "sky", as it was only known by that color. Obtaining these specimens of pure aerinite nowadays is almost impossible.

Blocky aerinite criptocristalline with fragments of dolerite included. Excellent color. Aerinite was used as a blue pigment in many Romanesque paintings in the Pyrenees between the 11th and 14th centuries. Its characteristic blue color varies from dark to pale blue. In fact, its name comes from a Greek root aerinos meaning "atmosphere" or "sky", as it was only known by that color.

Group of sphalerite crystals, with good brilliance, rich in crystal faces, some identifiable as dodecahedral. The specimen is translucent in some areas. A piece from a classic Spanish locality, Áliva. These specimens prized by collectors.

Small cubic crystal of thorianite, bright and well defined. Perhaps the most interesting aspect of the specimen is that it comes from the type locality for the species, in Sri Lanka. From the C. Prieto collection (Madrid).

Small cubic crystal of thorianite, bright and well defined. Perhaps the most interesting aspect of the specimen is that it comes from the type locality for the species, in Sri Lanka. From the C. Prieto collection (Madrid).

Xenotime-(Y) crystal from a classic Norwegian locality, close to the type locality for the species. Some crystal faces can be observed. This old specimen comes from the Prieto collection (Madrid).

55 €

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