Aesthetic specimen that combines an upper part formd by goethite botryoidal aggregates, with a semi-matt luster, and a lower part with stalactitic growths of manganese oxides. They are accompanied by hematite of intense red color and baryte. A very interesting specimen from "la Sierra de la Unión". 3o6x44

Sold

This specimen shows us a rich group of prismatic schorl crystals, with well defined terminal faces and striated prism. Intense black color and excellent brilliance. They are accompanied by albite and muscovite crystals.

Dadsonite is a rare chloro-sulfoantimonide of lead, compositionally differing from boulangerite by this chlorine anion (1 atom of Cl for 60 atoms of S!). In the "bad-lands" area of Sant Ponç (or Saint-Pons) there are lenticular levels of siderite and calcite. The formation of this rare sulfosalt is based on the redissolution of other sulfosalts in the presence of chlorides.
The fine needles of dadsonite usually appear included in calcite with siderite, along with boulangerite. Once the calcite is removed by chemical processes, needles emerge in all their beauty. It can also be found forming radial aggregates in matrix cavities. The dadsonite from Sant Ponç can probably be considered among the best worldwide.

Sold

Titanian hydroxylclinohumite porphyroblasts with white-greyish diopside and antigorite serpentinite. The varietal name titanoclinohumite (older literature uses the name "titanolivine" for this variety) is commonly used to indicate Ti-bearing hydroxylclinohumite found in metamorphosed serpentinites. A very interesting specimen from unusual locality for the species.

Sold

Group of very well defined fluorite crystals, between transparent and translucent, and with a yellowish-green color characteristic of this mine. Some have color zoning. They are accompanied by small crystals and hyaline quartz. These specimens that we offer were collected in the early 70s.

A good sized specimen formed by numerous albite crystals, pericline variety, due to its elongated prisms and white color. Well defined, bright and arranged in a matrix colored by orange microcline and schorl. This aesthetic specimen belongs from the former collection of Peter Seroka (Girona).

90 €

Buy

Twinned crystal of very good size from microcline, with very well defined faces, brilliant and white in color with orange stains. From what we can see, the main crystal is formed by a Carlsbad twin whose union plane is (010). It can be seen that the brilliance of both crystals is different. It is accompanied by albite (var. clevelandite) and muscovite. Microcline specimens such as this one can be considered among the best finds in recent years. It belonged to a great collector of feldspars such as Peter Seroka (L'Escala, Girona, Catalonia).

Rich specimen formed by globular aggregates of acicular crystals of light blue color, bright. They are accompanied by small prismatic malachite crystals and tiny dioptase crystals. A very brilliant and characteristic specimen for the species, rare in the market.

In this aesthetic specimen we can observe several small rhombohedral crystals, with an orange-yellow color, of this very rare strontium aluminum phosphate-sulphate. They are arranged on a matrix with magnesite and numerous crystals of brown fluor-uvite, very well defined and transparent.

These opals are rare. It is a variety with pink tones that is usually accompanied by sepiolite. Its name "Quincyite" comes from the French locality of Quincy, near Orleans, in the heart of . This specimen belongs from the E. Laskowski (USA) collection, but the piece has been in different collections, as the backside label says.

Sold

Group of very well defined fluor-uvite crystals with a characteristic olive green color, with an excellent transparence. They are disposed on a matrix formes by magnesite crystals, between transparent to translucent. The contrast with the matrix is very aesthetic. Most specimens historically designate as uvite are actually, as analyses have shown, the F-dominant end member: fluor-uvite. Those from this mine have been shown to be the fluorine phase.

In this specimen we can observe several almandine garnet crystals included in a matrix with violet-blue cordierite crystals, the pleochroism of which can be observed on the edges. The specimen belonged to the Peter Seroka collection.

Sold

Group of tabular chalcocite crystals, well defined and with polysynthetic growths on faces. Some present fractures where we can observe the metallic luster of the species. Specimens from this mine are rare on the market. It belongs from the former René Hubin collection (Neupré, Belgium) and is accompanied by the label. Nice miniature.

Sold

Group of diopside crystals with an intense green color, parallel growths, brilliant and translucent. A specimen of this classic Spanish locality from the Peter Seroka collection.

Sold

Rich group of tabular semseyite crystals forming brilliant rosettes. It is accompanied on the matrix with galena, chalcopyrite, sphalerite and some quartz. Nowadays, these specimens are not easy to find.

Cuprodongchuanite is a mineral species with the formula Pb₄CuZn₂(PO₄)₄(OH)₂ that has been approved very recently (IMA No. 2021-065); is the copper analogue of dongchuanite (IMA No. 2021-058) with the formula  Pb₄ZnZn₂(PO₄)₄(OH)₂. Both species form a series and belong to the dongchuanite group, together with the zheshengite Pb₄ZnZn₂(AsO₄)₂(PO₄)₂(OH)₂ and the cuprozheshengite Pb₄CuZn₂(AsO₄)₂(PO₄)₂(OH)₂. Distinguishing one species from another is only possible by elemental analysis. For this reason these specimens have been analyzed by SEM-EDS.

In this specimen we have determined the cuprodongchuanite. The presence of As is detected in all the specimens studied, which would indicate that we are in a term of the series with cuprozheshengite. It would be correct to label it cuprodongchuanite-cuprozheshengite. It appears as light green globular aggregates on the colorless hemimorphite. The bluish color on the specimen is veszelyite.

Sold

Cuprodongchuanite is a mineral species with the formula Pb4CuZn2(PO4)4(OH)2 that has been approved very recently (IMA No. 2021-065); is the copper analogue of dongchuanite (IMA No. 2021-058) with the formula Pb4ZnZn2(PO4)4(OH)2. Both species form a series and belong to the dongchuanite group, together with the zheshengite Pb4ZnZn2(AsO4)2(PO4)2(OH)2 and the cuprozheshengite Pb4CuZn2(AsO4)2(PO4)2(OH)2. Distinguishing one species from another is only possible by elemental analysis. For this reason these specimens have been analyzed by SEM-EDS.

In this rich specimen we have determined cuprodongchuanite aggregates. The presence of As is detected in all the specimens studied, which would indicate that we are in a term of the series with cuprozheshengite. It would be correct to label it cuprodongchuanite-cuprozheshengite. It occurs as light green globular aggregates on very well defined veszelyite crystals and on a matrix with hemimorphite.

Sold

Cuprodongchuanite is a mineral species with the formula Pb₄CuZn₂(PO₄)₄(OH)₂ that has been approved very recently (IMA No. 2021-065); is the copper analogue of dongchuanite (IMA No. 2021-058) with the formula  Pb₄ZnZn₂(PO₄)₄(OH)₂. Both species form a series and belong to the dongchuanite group, together with the zheshengite Pb₄ZnZn₂(AsO₄)₂(PO₄)₂(OH)₂ and the cuprozheshengite Pb₄CuZn₂(AsO₄)₂(PO₄)₂(OH)₂. Distinguishing one species from another is only possible by elemental analysis. For this reason these specimens have been analyzed by SEM-EDS.

In this specimen we have determined the cuprodongchuanite. The presence of As is detected in all the specimens studied, which would indicate that we are in a term of the series with cuprozheshengite. It would be correct to label it cuprodongchuanite-cuprozheshengite. It appears as light green globular aggregates on the colorless hemimorphite. The bluish color of the specimen is due to the fact that the hemimorphite covers veszelyite crystals.

Sold

Very good size specimen of celestine from this classic Spanish locality. In this specimen we can observe various botryoidal to stalactitic forms, one of them in the form of a bridge-curl, and which cover old celestine crystals, as evidenced by the rounded prismatic shapes.

Specimens of bavenite from Cadalso de los Vidrios are a classic of Spanish mineralogy and pieces of this beryllium and calcium aluminosilicate had not been seen for quite some time. In this good-sized specimen formed by parallel growths of microcline crystals with albite, we can observe numerous rosette-shaped aggregates of tabular bavenite crystals, well defined, brilliant, and colorless to slightly yellowish. The specimen belongs to a North American collection.

Sold

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.

A very good size specimen formed by several vugs covered by rosettes of hureaulite crystals with a tabular shape. Crystals are transparent to translucent, well-defined and with a very characteristic light brown color. The matrix is formed by other phosphates such as rockbridgeite, almost black in color. Specimens of this quality and with this size are not easy to find. A museum piece.

This sample comes from the Freiberg Bergakademie and is accompanied by a label from the end of the 19th century and beginning of the 20th. In this old label we can read that the specimen was identified as monazite. To corroborate this fact together with the other accompanying minerals, we proceeded to carry out analyzes by SEM-EDS. The results indicated that the crystals from honey to dark tones, with a vitreous luster, correspond to monazite-(Ce), which is accompanied by rare earth elements such as neodymium or lanthanum, replacing cerium. We also detected the presence of thorium, which explains why the piece shows some radioactive activity. In the potassium feldspar matrix, with quartz, we can observe small black crystals with a metallic luster that would correspond to of the columbite-(Fe)-columbite-(Mn) series. We have also detected a thorium phosphate-silicate with REE and aluminum traces, with a composition similar to enalite, an independent member of the xenotime-thorite group, although we have not been able to confirm it. We will send the buyer all the analyzes that give this specimen a remarkable mineralogical value.

Sold

This specimen from the Freiberg Bergakademie is accompanied by a very old label, probably from the early to mid-19th century, along with a more "modern" one. When in doubt about the description of the labels, we proceeded to analyze the specimen using SEM-EDS. By this spectroscopic technique we have been able to confirm that the beige crystals included in the piece are titanite. The white matrix corresponds to potassium feldspar, most likely microcline, and the black elongated prismatic crystals correspond to aegirine-augite. It is a historical specimen from a Norwegian locality known for centuries for mining magnetite in skarns. We will send all analyzes to the buyer.

Sold

These specimens, although not remarkable for their great beauty, do present historical interest to many collectors. According to the old label that accompanies it, the place where it was collected indicates that it is the "pic d'Espada" (Sword peak) and in French territory. After several inquiries, we can place this peak in the Varètja area, in the French High Pyrenees, in Occitania, north of the Spanish border with the Ordesa y Monte Perdido National Park. We can observe numerous black dodecahedral crystals of andradite-grossular, melanite variety, which in the past were given the name "pyreneite". It is accompanied by the 19th century handwritten label of Dr. Hugo Francke (Dresden).

Sold