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RM1436   Ettringite with Manganite

N'Chwaning II Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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.

 

RM1050   Hematite

N'Chwaning III Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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


Price: 40 €Buy
 

RM813   Hausmannite

N'Chwaning II Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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.

 

RM650   Apophyllite-(KOH)

N'Chwaning II Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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.

 

RM599   Kutnohorite with Manganoan Calcite

N'Chwaning II Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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
 

RM588   Poldervaartite-olmiite with xonotlite

N'Chwaning II Mine, Kuruman, Kalahari manganese fields, Northern Cape, South Africa

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.
 
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