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Stalactitic aggregate, pineapple shape, of amethyst quartz crystals. Brilliant and with a more intense "amethyst" color at the tips of the crystals. An aesthetic piece, common, but aesthetic... It belongs to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.
An interesting specimen of turquoise (variety rashleighite) from the Cornwall mines. Formerly, rashleighite was an approved species, now it is defined as a turquoise with a certain iron content, intermediate between chalcosiderite and turquoise. This sample shows a sky blue crust aggregates, with cavities with crystals and a quartz matrix. A Cornish classic from the collection of Joan Astor (Barcelona) and, previously, from Martín Oliete (Madrid), a well-known systematic collector.
Sulphur specimens from Conil (Cádiz, Andalucía) are highly valued among mineral collectors on the Iberian Peninsula. In this specimen we can see various sulfur aggregates, one of them in the form of a dipyramidal crystal. They are disposed in cavities lined with calcite. The banding of the matrix is perfectly observed. A classic locality for fine crystallized sulfur specimens since 18th century. Probably the area has been worked since Roman times. Very difficult to see in the market. Interesting video of sulphur mines from Conil [video].
Rich group of hemimorphite crystals forming radial aggregates, with a slightly bluish hue. It is accompanied by black, zoned, tenorite globular aggregates. It belongs to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.
Petalite is one of those minerals that today are in the sights of mining companies since it is an aluminum and lithium silicate, lithium is an essential element for the manufacture of batteries. A exfoliated very good size and shiny specimen.
A very aesthetic miniature formed by various octahedral crystals of fluorite, with a violet to purple color, which contrast on the white quartz matrix. Defined, translucent and with brilliance. The Pine Canyon deposit in New Mexico has been known for more than 20 years and are prized for its fluorite crystals.
Brilliant aggregate of tabular azurite crystals with this intense and characteristic color. A very aesthetic specimen of this classic Moroccan town. It comes from the Joan Astor collection (Barcelona) who acquired it from Marçal Llòria, from "Lloid-Material de Ciencias Naturales", a well-known Barcelona mineral seller.
Very rich specimen formed by aggregates of prismatic crystals of mimetite, transparent, forming sheaves and divergent growths. The yellow-orange color and luster make them stand out on a matrix with romobohedral calcite crystals. A classic from the 1960s to 1970s.
These tspecimens from Les Malines are very rare today. Twinned aggregates of bournonite crystals, partially covered by cube octahedral galena, pyrite and sphalerite. They are disposed on a matrix of baryte crystals. These are classics of the largest deposit of lead and zinc in France, whose exploitation dates back to Roman times.
Exceptional specimen of opal, fire opal, with an intense orange to reddish color, with brilliance and transparence observed since it is an opal nodule with two light inputs. All light. It is enclosed in a very hard rhyolitic matrix. These are sometimes also called as "jelly opals" due to their unique color and waxy luster. This specimen was acquired by Joan Astor, at the end of the 80s, from the well-known Enric Kucera (Barcelona), a great connoisseur of Mexican mines. A gem.
Group of skutterudite crystals, intense luster and well defined faces and edges, showing cube, octahedron and dodecahedron shapes. They are accompanied by white calcite with which they contrast. It belongs from this classic Moroccan mine and from the Joan Astor collection.
Although the label of this specimen places the piece in Mozambique, we have no record of graphite specimens similar to this one in this African country. For another specimen from the same collection (Joan Astor) we can place it in the classical sites of the Ratnapura area, in Sri Lanka. Fibrous crystals with luster. More information can be found in the file of the specimen RM1836 [click here]. Very interesting classic.
Brilliant black andradite crystals, var. melanite, on contrasting light matrix. Well defined faces and edges. Very aerial. From the former Joan Astor collection (Barcelona).
A very hard to find enstatite specimen from the Ødegården apatite mines. Prismatic crystal of dark greenish-brown, partially transformed to talc. Accompanied by muscovite. During the 2nd World War, the mines were worked from 1941-1945 under the leadership of Adam Petterson. The mines are now closed and most of the dumps are overgrown by forest. Some of the dumps have been used as masses in construction and reparations of roads in the district.
Pyrolusite specimens from Sagides (Soria) are rare on the market. In this specimen we can see bright aggregates of fine prismatic pyrolusite crystals. They are partially covering a goethite matrix.
Classic ruby crystals, with an intense purple color, arranged in a quartz-rich matrix. Especially rich and aesthetic specimen from India. The crystals are sharp, bright and translucent. They fluoresce under UV light. Former Joan Astor Collection.
Arborescent specimen of native copper, formed by numerous sharp crystals, with excellent luster and intense color. The piece is from the Joan Astor collection and dates from the early 70s.
These specimens are very rare in this classic locality for the rutile. The matrix is formed by interpenetrating tabular kyanite crystals coated with iridescent shades of 'turgite', a term used for the mixture of goethite and hematite. What is remarkable is a group of rutile crystals, very bright and well defined. A piece with history.
Achtaragdite is a unique, rare and poorly understood pseudomorph, from this remote Siberian locality that is the Type Locality for grossular garnet. It is a variety of the grossular-hibschite garnet series and is (technically, according to mindat) a hydrogrossular-chlorite-carbonate pseudomorph after what was formerly considered to be wadalite or some other rare hydrogarnet. The real precursor mineral for these pseudomorphs is now considered to be helvite.
Andalusite specimen from Cap de Creus (Cape), with pink tones and quite crystalline. The Cap de Creus Natural Park was the first maritime-terrestrial park in Catalonia. It was created in 1998 and protects a large part of the Cap de Creus peninsula. Currently totally prohibited to collect minerals in this area.
Very bright opal from this Australian locality, with orange colors, the elongated dendrites of pyrolusite give it an aesthetic touch. This locality is formed by basaltic rocks over an area of more than 1000 km², most of them north and south of the Dawes mountain range. The main period of volcanic activity was at c. 25Ma. Acquired by Joan Astor from the well-known Jaume Serrate (Terrassa), whom we could describe as a "craftsman" of minerals.
This locality is known for its production of "moonstone", extracted from altered pegmatites. It is an unpolished specimen, very crystalline, translucent, with slightly greenish tones, and a very characteristic light effect called adularescence. Thin alternating layers of orthoclase and albite create the light interference in this material that is responsible for this effect. Moonstone is a feldspar close to orthoclase and microcline.
Another well-known locality for celestite specimens in La Segarra (Lleida) is the Tossal Gros quarry (Can Fontanella or Roca quarry). Oligocene lacustrine marls, marly limestones and limestones containing geodes with diagenetic celestite. The grayish matrix is very characteristic. The prismatic, acute crystals, between transparent to translucent, are disposed in the cavities of the marl rock. They are accompanied by calcite crystals. A classic of Catalan mineralogy.
Another well-known locality for celestite specimens in La Segarra (Lleida) is the Tossal Gros quarry (Can Fontanella or Roca quarry). Oligocene lacustrine marls, marly limestones and limestones containing geodes with diagenetic celestite. The grayish matrix is very characteristic. The prismatic, acute crystals, between transparent to translucent, are disposed in the cavities of the marl rock. They are accompanied by calcite crystals. A classic of Catalan mineralogy.