Rosell Minerales

Globular aggregates of white acicular crystals with a silky luster of oyelite, a rare calcium borosilicate, which are accompanied by very brilliant, transparent and well-defined calcite crystals. Nowadays these specimens are quite difficult to be found. It belongs from the Nicolau collection (Barcelona) and it is accompanied by the handwritten label.

Size: 4.7 x 4.4 x 3.5 cm.

Col. E. Nicolau (Barcelona).
Classic locality

Excellent specimen formed by numerous colorless acicular crystals of bultfonteinite, a rare hydrated calcium fluorosilicate, which is accompanied by beige prismatic crystals of olmiite, a hydroxysilicate of calcium and manganese. The specimen is very representative of these species. This is the type locality for olmiite. We include pooldervaartite because it is very common since it forms a series with olmiite.

Size: 7.2 x 5.7 x 4.9 cm.

Col. E. Nicolau (Barcelona).
Type Locality

Rich group of prismatic crystals of gaudefroyite, a rare calcium and manganese borate-carbonate, with an intense black color. They are accompanied by brilliant hematite crystals, along with barite, calcite and orange andradite.

Size: 7.3 x 5.5 x 4.5 cm.

Col. M. Ecker (Deutchland). Col. E. Nicolau (Barcelona).
Classic locality

Rare and good sized mangan-diaspore (diaspore with manganese) specimen showing brilliant, transparent to translucent, burgundy red tabular crystals disposed in an arc on matrix. We can also observe small geodes full of crystals. The Glosam Mine specimens are the only ones in the Kalahari area in which the manganese diaspore shows this intense color and brilliance. An exceptional specimen for a little-seen species.

Size: 10.2 x 8 x 6.2 cm.
Main crystal: 12 mm.

Good size specimen of purple, from the old Arguijo collection.

Size: 7.7 x 6 x 5.7 cm.
Found in ±1985.

Col. A. Arguijo (L'Hospitalet de Llobregat, Barcelona).

A good-sized specimen of this monoclinic amphibole named grunerite, which in its fibrous form is called "amosite". The name has also been used to refer to other members of the group, and form series with cummingtonite. Grunerite is defined as a monoclinic amphibole belong to the magnesium-iron-manganese amphibole subgroup. A worldwide classic from this South African locality.

Size: 7.0 x 3.8 x 3.0 cm.

Excol. Lluís Daunis & Maria Ruscalleda.
Classic locality

Group of well developed ettringite crystals showing a pseudohexagonal prism, rich in terminal faces. This specimen has a rare toasted honey tone for the species and it is believed to be due to exposure to sunlight out of the mine. This sample is accompanied by many sharp manganite crystals, very brilliant, some twinned, and with an intense black color. An unusual specimen for this classic mine collected in 1985.

Size: 2.3 x 2.2 x 1.4 cm.
Main crystal: 22 x 6 mm.
Found in 1985.

Very good specimen of bultfonteinite forming white acicular crystals, with prisms slightly beige to orange of olmiite. Two rare species from a mining area well known for systematic collectors. Accompanied by tabular celestine crystals. Good size and better quality.

Size: 7.7 x 5.5 x 4.0 cm.

In this specimen we can see a group of lenticular sturmanite crystals, brilliant, with well defined faces and edges. Color is yellow to greenish. Noted for its size and transparency. A very good choice...

Size: 4.5 x 3.0 x 1.4 cm.
Main crystal: 12 x 10 mm.
Found in 2014.

In this specimen we can enjoy a rich group of lenticular sturmanite crystals orange, bright, with a yellow to orange color, transparent and with very sharp faces and edges. It is accompanied by rosettes of greenish brucite, a magnesium hydroxide. In the same specimen there are two very interesting species for systematic and aesthetic collectors.

Size: 4.3 x 3.4 x 2.8 cm.
Main crystal: 4 x 3 mm.
Found in 2014.

Most people do not know that these come from anywhere but Utah, but here is a Kalahari Manganese fields bixbyite specimen. A druse of highly lustrous, very sharp interpenetrated cubes of black bixbyite from this famous locality. An excellent specimen for the locality. A true rarity.

Size: 3.8 x 3.5 x 2.0 cm.
Main crystal: 8 x 7 mm.
Found in 2012.

Very good specimen of bultfonteinite forming white acicular crystals, with prisms slightly beige to orange of olmiite. Two rare species from a mining area well known for systematic collectors. Accompanied by tabular celestine crystals. Good size and better quality.

Size: 6.0 x 4.3 x 3.9 cm.
Found in 2004.

Group of very sharp hematite crystals, one of them of greater size and rich in faces. We can observe the positive and negative rhombohedrons truncated by the pinacoid and perfectly visible the hexagonal dipyramid well developed. Metallic luster is excellent and it has an intense black color. A very interesting speciemen of this South African mine.
It comes from the specimens of Luis "Louie" Bravi Antonio Teixeira Leite (1942-1999), a Portuguese mineral dealer who lived many years in South Africa.

Size: 2.8 x 2.5 x 2.5 cm.

Ex-coll. M. Ecker - Louie Leite

Excellent aggregate of acicular crystals of this uncommon mineral from a classic mine for the species. The sample dates from the early 1990s and is currently difficult to get pieces with this aesthetic.

Size: 4.4 x 3.0 x 2.8 cm.
Found in 1992.

Ex-col. M. Ecker.

This specimen shows parallel growths on a single axis, so typical of the finds from N'Chwanning mine. The tetrahedral crystals are brilliant with very well defined faces and edges and showing echeloned and skeletal growths. Good size for species.

Size: 4,8 x 3,4 x 2,3 cm.

The mine N'Chwaning II is well known worldwide for their specimens of olmiite or rhodochrosite, among many other mineral species. But this mine has also provided excellent samples of hydroxyapophyllites which are very different from the Indian specimens or any others. This is one of them, perhaps the best I've never seen.
A group of very aerial interpenetrated apophyllite-(KOH) crystals, very sharp. They show striated and defined pseudocubic prisms with small triangular faces of the tetragonal dipyramid on the dihedral angles. Very brilliant, translucent and with an excellent aesthetics. In addition, it presents isolated crystals on the matrix.

Size: 9,5 x 8,0 x 4,8 cm.
Main crystal: 9 x 8 mm.
Found in ±2000.

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.