Rosell Minerales

Group of very sharp fluorite crystals which show good transparency and lilac to purple color. They are disposed on a matrix with feldspar and smoky quartz, accompanied by small prismatic crystals of brilliant prismatic stilbite, transparent and vivid orange color. Also with groups of clinochlore crystals, with dark brown to nearly black color.
This specimen was collected from miarolitic pegmatites veins in granite of the Strzegorn-Sobótka massif quarries. These quarries are worked for aggregates and miarolitic cavities are scarce. These specimens are coveted by collectors, mainly German and Poles, unusual in other collections.

Size: 4,7 x 4,5 x 2,7 cm.
Main crystal: 22 x 20 mm.

The kamotoite-(Y) are the intense yellow crystalline sprays, with individual flat-laying crystals to 5 mm. In the same sample we can observe probably a small vein of yellow to orange brilliant uranophane.Kamoto is the Type Locality for the species. A very rare uranium and ytrium mineral from Katanga.

Size: 4,4 x 2,0 x 1,8 cm.

Presents radioactive activity.

Nice specimen from the former mineral collection of Henri-Léon Ungemach (1879-1936). The sample corresponds to the label. Sometimes is difficult this relation, or specimen has no number on or number do not match.

The cavity is covered by scalenohedral calcite crystals, and on them groups of brilliant galena and pyrite. We can observe some idiomorphic crystals, with defined faces and dull luster, of stephanite. A sample with its own history.

 

Size: 6,8 x 3,7 x 3,2 cm.
Main crystal: < 1 mm.
Found in 1890's.

Ex-col. Henri-Léon Ungemach (1879-1936).

Unusually species for this Moroccan mine. The dealer confirmed the locality, I initially thought in Imiter. This is a group proustite crystals with good red color, brilliance and transparence, some of them contacted due to the cavity, others showing terminations and striated faces. In calcite matrix.

Size: 6,0 x 5,2 x 3,7 cm.
Main crystal: 4 x 1 mm.

A huge size specimen of malachite that has completely replaced azurite former crystals, preserving its prismatic shape, with visible terminal faces. Malachite has an intense green color, with silky luster due to its acicular shape, fibrous. With a minor rocky matrix. An elegant specimen of a classic mine as Touissit.

Size: 7.5 x 6.8 x 4.5 cm.
Main crystal: 4.2 x 2.0 cm.
Found in 1990's.

Let me add another "delicious" specimen of kutnohorita with manganoan calcite. Kutnohorite is a rare member of dolomite group, a calcium carbonate with manganese, magnesium and few iron... uncommon. In the specimen appears as acicular snowy white crystals on which have grown a large group of pink crystals of calcite with manganese. Good brilliance and calcite extremely fluorescent with reddish tone. In the back side we can observe a particular radial aggregates of kutnohorite, this is another shape of the species. We have both in the same sample... The aesthetics of the formations is unquestionable and the species is a classic hard to find.

Size: 10,0 x 10,0 x 6,5 cm.
Found in 2009.

Fluorescent under LW-UV and SW-UV lights

This huge size specimen combines two very interesting species. On one hand we have spherical aggregates formed by radiated polysynthetic growth of poldervaartite, showing slightly curved top faces, with a very uniform beige and good luster. We would like to inform you that these specimens were found in the mine in late 2010 and were collected very few specimens. They were analyzed by SEM-EDS, and it was found that the external and surface crystals were mainly determinated as poldervaartite, while the inner concentric growths presents poldervaartite and olmiite mixture. This makes us confirm poldervaartite in this mine.
Only for this species this sample is excellent. But it is accompanied by xonotlite, an uncommon calcium silicate, in the form of fine needles, brilliance and flexible. A stunning combination. To increase its interest we can say that this sample is one of the few of this vug, from this popular South African mine. A great opportunity. We will send the analysis to the buyer.

 

Size: 9,5 x 7,5 x 5,0 cm.
Found in 2010.

Ex-col. M. Ecker.

A huge size crystal of betafite showing defined octahedral faces (triangular) and developed dodecahedral ones. Very interesting for its crystallography and species. An oldie, classic and representative for the species. This specimen belonged to the collection of P. Sainfeld, mineralogist at the École des Mines de Paris.
Although the term betafite was discredited in 2010, many of us still are using this term to define this mineral when we see it. Our specimen is an uranium, calcium, titanium and niobium/tantalum oxide with radioactive activity. Currently the betafite is included as a variety within the pyrochlore supergroup. As a note, the rich uranium term has been only found in the Moon (oxyuranobetafite).

Size: 5,6 x 4,0 x 3,6 cm.
Found in 1960's.

Ex-col. Sainfeld (École Mines Paris).
Presents radioactive activity.

A huge size crystal of betafite showing defined octahedral faces (triangular) and developed dodecahedral ones. Very interesting for its crystallography and species. An oldie, classic and representative for the species. This specimen belonged to the collection of P. Sainfeld, mineralogist at the École des Mines de Paris.
Although the term betafite was discredited in 2010, many of us still are using this term to define this mineral when we see it. Our specimen is an uranium, calcium, titanium and niobium/tantalum oxide with radioactive activity. Currently the betafite is included as a variety within the pyrochlore supergroup. As a note, the rich uranium term has been only found in the Moon (oxyuranobetafite).

Size: 5,5 x 4,5 x 4,3 cm.
Main crystal: 4,3 x 4,0 cm.
Found in 1960's.

Ex-col. Sainfeld (École Mines Paris).
Presents radioactive activity.

From a classic German locality: Alberoda bei Aue. This locality is known by its silver sulphosalts, but not well represented in collections. This sample is very rich in brilliant stephanite crystals and some reddish pyrargyrite. An old specimen, old label and quality.

Size: 6,0 x 5,2 x 3,5 cm.
Main crystal: 4 x 3 mm.

Ex Dr. Krantz, Bonn.

Group of octahedral crystals of this unusual nickel sulfoarsenide. It shows very bright faces and defined edges. The luster, tet me emphasize, is exceptional. Disposed very aerial on a matrix of calcite. This specimen has NOT been acidified to remove calcite as is usual in many specimens what may compromise their future stability. A good choice.

Size: 6,8 x 3,5 x 1,8 cm.
Main crystal: 13 x 8 mm.

Precio reducido-Reduced price 80€

Recent mineral find and novelty at Sainte-Marie-aux-Mines 2013. An rich and aesthetic group of prismatic cerussite crystals, with white color, translucent, brilliant, very acute and complex terminations and good size. With striated faces. Contrasting very aerial on the matrix.

The lead and silver mine of Lescure was worked in Roman times and there are documents from the late eighteenth century telling us about these mines. Although "serious" mining operations are confirmed from 1808-29 until its closure in 1951. These specimens are known in long crystals, and since the 90s had not been obtained pieces of this quality. Today the mine is closed and collapsed (Le Règne Mineral, 85, 2009).

Size: 8,0 x 7,7 x 5,8 cm.
Main crystal: 24 x 4 mm.
Found in 04-05/2013.

Fluorescent under long wave UV

Recent mineral find and novelty at Sainte-Marie-aux-Mines 2013. A very rich group of prismatic cerussite crystals, with white color, translucent, brilliant, very acute and complex terminations and good size. With striated faces. Contrasting very aerial on the matrix.
The lead and silver mine of Lescure was worked in Roman times and there are documents from the late eighteenth century telling us about these mines. Although "serious" mining operations are confirmed from 1808-29 until its closure in 1951. These specimens are known in long crystals, and since the 90s had not been obtained pieces of this quality. Today the mine is closed and collapsed (Le Règne Mineral, 85, 2009).

Size: 7,5 x 4,6 x 3,2 cm.
Main crystal: 21 x 4 mm.
Found in 04-05/2013.

Fluorescent under long wave UV

A novelty at Sainte-Marie-aux-Mines 2013. Globular aggregates of tabular hemimorphite crystals showing an intense blue color and good luster. This blue color is unusual for the species and in relatively few deposits can be observed, it is usually colorless. The specimen is peppered by groups of very sharp cerussite crystals with good brilliance, some of them partially covered bay a black microcrystals, showing prismatic crystals and cyclic twins. From a recent find at the Kimbedi copper mining area in the Republic of Congo (Congo Brazzaville).

Size: 8,0 x 6,0 x 4,0 cm.
Main crystal: 8 x 7 mm (aggr.).
Found in 06/2013.

A novelty at Sainte-Marie-aux-Mines 2013. Globular aggregates of tabular hemimorphite crystals showing an intense blue color and good luster. This blue color is unusual for the species and in relatively few deposits can be observed, it is usually colorless. The specimen is peppered by groups of very sharp cerussite crystals with good brilliance, some of them partially covered bay a black microcrystals, showing prismatic crystals and cyclic twins. The sample is from a recent find at the Kimbedi copper mining area in the Republic of Congo-Brazzaville.

Size: 7,7 x 5,3 x 2,5 cm.
Main crystal: 6 x 6 mm (aggr.).
Found in 06/2013.

A high quality specimen from the famous Carrara Marble quarries of Italy. The ancients believed that the water solidified in the form of hyaline quartz crystals... Viewing this specimen, its purity, transparency, brilliance and perfection, perhaps we can understand their interpretation. Undamaged crystals, one almost doubly terminated and on snowy white marble matrix, partially covered by tiny crystals of calcite. An Italian gem.

Size: 6,0 x 4,5 x 4,0 cm.
Main crystal: 13 x 12 mm. (aggr.)

Group of very sharp quartz crystals with inclusions of clinochore, transparence, luster and aesthetically disposed on a K-feldspar (adularia) crystals as a matrix.Very aesthetic and from a unusual locality.

Size: 7,5 x 3,8 x 2,7 cm.
Main crystal: 45 x 6 mm.
Found in 2011.

Interesting specimen of aegirine showing defined prisms with an intense color almost black, brilliance and sharp, prismatic and marked terminal faces. They are accompanied by a some groups of zircon crystals in parallel growth, showing the tetragonal prism and dipyramids. Good orange to yellowish tones, some transparency on edges and disposed in aerial way on aegirine matrix.

Size: 5,8 x 4,0 x 3,5 cm.
Main crystal: 11 x 8 mm.

On a compact quartz matrix we have different groups of cobaltoan calcite crystals with intense purple to fuchsia color, with transparence and well defined faces and edges. It is accompanied by spherical aggregates of snowy white dolomite and some quartz crystals. A classic from Katanga Copper Crescent mines.

Size: 5,4 x 4,3 x 4,9 cm.
Main crystal: 6 x 2 mm.

This specimen shows spherical aggregates of plancheite, formed by several acicular crystals in a radiated shape. On the surface of the spheres we can enjoy curious honeycomb structures. Color is between blue and blue-gray. On a vug layered by small quartz crystals. From a locality not well represented in collections for this species.

Size: 7,5 x 5,7 x 5,0 cm.
Main crystal: 4 x 4 mm.

Group of sharp vivianite crystals forming a perfect and aesthetic radial aggregate, not usual for the locality. Excellent brilliance and intense deep green color, visible at the terminal faces of the crystals. These minerals appear in phosphate vein, in fossiliferous areas, the phosphate source. Classic in this area are anapaite specimens in fossil brachiopods.

Size: 4,0 x 3,7 x 2,2 cm.
Found in 2001.

A single and sharp crystal of bastnäsite-(Ce) showing tabular hexagonal shape. They show a good transparency and color that varies between yellow-green to orange-brown, depending on the type of the light that strikes them. Accompanied by corroded allanite-(Ce) as usual in this paragenesis. This specimen is from a French worldwide classic mine for Rare Earth Elements (REE) species: Trimouns. Currently it is not easy to find bastnäsite-(Ce) specimens from this mine and with this crystal size.

Size: 5,9 x 4,8 x 3,3 cm.
Main crystal: 6 x 5 x 1 mm.
Found in 2006.

It shows Pleochroism

A very rich specimen formed by several azurite crystals that have been pseudomorphed by malachite showing original lanceolated forms, also tabular crystals with  velvety faces due to fibrous malachite. Azurite, with deep color, crystals also observed partially converted into malachite. The brilliance of both minerals is really good, with superb aesthetics. From a mine not well represented in collections and which nowadays is difficult to obtain fine mineral specimens.

Size: 5,1 x 4,7 x 3,5 cm.
Found in 2007.

A floater aggregate of lanceolated sharp azurite crystals with an excellent color and luster, with small malachite pseudomorph after azurite growths. From a mine not well represented in collections.

Size: 3,5 x 3.0 x 2,7 cm.
Found in 2007.

In this specimen we observe groups of brilliant galena crystals showing complex forms with parallel growths. Accompanied by some isolated groups of djurleite crystals, those are distinguished by having less brilliance, greyish tone and iridiscent reddish reflections. Prisms are presented as complex forms, rich in faces, with striations and twinned. Djurleite is an uncommon copper sulfide closely related to chalcocite. Published in LAPIS (2014).

Size: 7,5 x 5,0 x 3,0 cm.
Main crystal: 8 x 3 mm.