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Molybdenite specimens from Inca del Oro are very difficult to find in the market and more with defined crystals. This sample shows a very well defined, bright and well-disposed hexagonal crystal of molybdenite on the matrix. A unique opportunity to include to your collection a very representative and fine specimen for the species. It belongs from the former J. Astor collection (Barcelona). The locality of Inca del Oro is located between the Chilean provinces of Copiapó and Chañaral.
Very interesting specimen of opal with opalescence of violet, blue, green colors that fill the fissures of a xylopal. Very aesthetic due to its arrangement in veins, contrasting with the sienna warm colors of fossil wood. This Australian locality is known for opalized pineapples. Specimens from this locality are difficult to find.
Druse of quartz crystals, milky to hyaline at the tips, with a certain reddish hue. It comes from a Moroccan locality unknown in collections, located in the Boulemane area, north of Aouli. Formed in volcanic rocks.
An extremely glassy opal specimen, transparent to translucent, with bluish to golden tones. An excellent specimen of opal from this classic American locality. It shows some fluorescence under ultraviolet (LW) light. An old piece from the A. Trigo collection (Mataró).
Group of very sharp cubic crystals of fluorite, very transparent, colorless, brilliant and in staggered growth. It presents certain very curious inclusions. Minos matrix of galena. Very aestetic. From the former Trigo Collection (Mataró).
Group of very acute scalenohedral calcite crystals, well defined and with a brown colour due to inclusions. Thanks to some of these crystals that show exfoliation, we can observe that it has been formed in the final stages of their growth. From the A. Trigo collection (Mataró).
Good size sample of the meteoric impact that took place aproximately 49,000 years ago in this remote area of Arizona. The impact crater stands out, where more than 30 tons of material have been collected since was discovered in 1891. It is a metallic, iron-nickel meteorite, classified as coarse octahedrite. Contains taenite (Fe, Ni) and mostly iron, kamacite variety (Fe, Ni). Weight: 23 grams.
Elongated single crystal of orange-pink childrenite without matrix. Transparent to translucent, with brilliance and defined terminal faces and altered prism.Very unusual for the species. From the former A. Trigo collection (Mataró).
Glendonite is the name given to the pseudomorphic calcite after ikaite. Ikaite, a hexahydrated calcium carbonate, was first observed in nature in the 1960s, at the seabed of the Ikka Fjord in Greenland. There, it precipitates due to the mixture of cold water submarine springs (3°C) rich in carbonates with seawater. Ikaite deposits are not usually found due to its poor stability, however, sometimes the rapid conversion of ikaite to calcite and water results in the generation of pseudomorphic calcite aggregates in the shape of the ikaite crystal (so-called glendonites). These calcite pseudomorphs directly replace ikaite above 4ºC.
Good sized fluorite crystal from this classic North American mine. It shows the cube shape with staggered growths on one edge, along with polysynthetic growths on the faces. Translucent to transparent, bright and with a violet tone that shows geometric color zoning, more intense on the edges. With a minor "matrix" of sphalerite.
Aesthetic specimen of calcite crystals that form this semi-globular aggregate, with luster. It is accompanied by a small matrix with quartz and chalcopyrite crystals. A classic from the Romanian mine of Boldut; from the A. Trigo collection (Mataró). It shows an intense fluorescence under LW-UV light.
Hemispherical aggregate of smithsonite crystals, of good size, luster and with a very curious orange-brown color. On the label of the A. Trigo (Mataró) collection it indicates that he bought this specimen from a Moroccan dealer (1989) as "tornuisite", a term for which we have not found references, unless it was wrongly confused with "tarnowizite". Touissit specimens of globular smithsonite are known but rare.
Globular aggregates of prismatic natrolite crystals, with well defined terminal faces. It comes from a locality well known for its zeolites. Nowadays this Cape Grim area is restricted access due to wind turbines field. From the former A. Trigo Collection (Mataró).
Globular aggregate of prismatic natrolite crystals, with well defined terminal faces. It is disposed very aerially on the matrix. Specimens on matrix are unusual. It comes from a locality well known for its zeolites. Nowadays this Cape Grim area is restricted access due to wind turbines field. From the former J. Astor Collection (Barcelona).
These specimens of manganite partially replaced pyrolusite, come from a locality not yet described in the mineralogical bibliography. This deposit is located in the province of Boulemane, in the Fez-Meknés region, about ten kilometers from the well-known Aouli mines. It is a formation very similar to that of Imini (near Ouarzazate). These manganese deposits, both in Imini and in the Boulemane area, were formed in a karst system. Associated with shallow marine dolomites of the Cretaceous age and that currently form sub-horizontal mantles cutted by erosion, overlaping areas of volcanic rocks. Manganese minerals are found in dolomite breccia and ferruginous clays. We have carried out X-ray diffraction studies showing us the presence of both species: manganite and pyrolusite.
These specimens of manganite partially replaced pyrolusite, come from a locality not yet described in the mineralogical bibliography. This deposit is located in the province of Boulemane, in the Fez-Meknés region, about ten kilometers from the well-known Aouli mines. It is a formation very similar to that of Imini (near Ouarzazate). These manganese deposits, both in Imini and in the Boulemane area, were formed in a karst system. Associated with shallow marine dolomites of the Cretaceous age and that currently form sub-horizontal mantles cutted by erosion, overlaping areas of volcanic rocks. Manganese minerals are found in dolomite breccia and ferruginous clays. We have carried out X-ray diffraction studies showing us the presence of both species: manganite and pyrolusite.
These specimens of manganite partially replaced pyrolusite, come from a locality not yet described in the mineralogical bibliography. This deposit is located in the province of Boulemane, in the Fez-Meknés region, about ten kilometers from the well-known Aouli mines. It is a formation very similar to that of Imini (near Ouarzazate). These manganese deposits, both in Imini and in the Boulemane area, were formed in a karst system. Associated with shallow marine dolomites of the Cretaceous age and that currently form sub-horizontal mantles cutted by erosion, overlaping areas of volcanic rocks. Manganese minerals are found in dolomite breccia and ferruginous clays. We have carried out X-ray diffraction studies showing us the presence of both species: manganite and pyrolusite.
These specimens of manganite partially replaced pyrolusite, come from a locality not yet described in the mineralogical bibliography. This deposit is located in the province of Boulemane, in the Fez-Meknés region, about ten kilometers from the well-known Aouli mines. It is a formation very similar to that of Imini (near Ouarzazate). These manganese deposits, both in Imini and in the Boulemane area, were formed in a karst system. Associated with shallow marine dolomites of the Cretaceous age and that currently form sub-horizontal mantles cutted by erosion, overlaping areas of volcanic rocks. Manganese minerals are found in dolomite breccia and ferruginous clays. We have carried out X-ray diffraction studies showing us the presence of both species: manganite and pyrolusite.
Very well defined zunyite crystals, with luster and on matrix. The intense tile colour is due to hematite inclusions. With clean tetrahedron shape, truncated by cube faces. The edge of both tetrahedrons measures 8 mm. They are included in a small matrix of hematite. A crystallographic specimen of this mineral species, a rare aluminum chlorine sorosilicate with fluorine. We performed some X-ray diffraction studies that confirmed the species. We recommend an interesting article about this Iranian deposit in the magazine Rocks and Minerals (Vol. 95, nº 2, 2020).