Rosell Minerales

Specimen of alumoåkermanite (IMA2008-049) from the pegmatites of the Kola peninsula. Honey coloured. It is probably accompanied by species such as cebollite and juanite those form a whitish vein. A very rare species, very visible in the polished section. Good size. It comes from the southern part of the Kola Peninsula.

Size: 3.5 x 3.1 x 1.9 cm.

Glendonite is the name given to the pseudomorphic calcite after ikaite. Ikaite, a hexahydrated calcium carbonate, was first observed in nature in the 1960s, at the seabed of the Ikka Fjord in Greenland. There, it precipitates due to the mixture of cold water submarine springs (3°C) rich in carbonates with seawater. Ikaite deposits are not usually found due to its poor stability, however, sometimes the rapid conversion of ikaite to calcite and water results in the generation of pseudomorphic calcite aggregates in the shape of the ikaite crystal (so-called glendonites). These calcite pseudomorphs directly replace ikaite above 4ºC.

Size: 6.1 x 2.2 x 1.7 cm.
Found in ca. 1995.

Col. Antonio Trigo (Mataró).

Aggregate of brown prismatic crystals of this rare niobium and tantalum silicate found in the alkaline pegmatites of the Khibiny Mountains, in this remote area of the Kola Peninsula. It is accompanied by pink aggregates of schizolite, an intermediate member of the pectolite-serandite series, and of lamprophyllite. Identified by Dr. D. Lisitsin.

Size: 5.6 x 3.8 x 2.8 cm.
Main crystal: 1.7 cm.

Lorenzenite is a rare sodium titanium silicate found in pegmatites and nepheline syenites. A lustrous, sharp, chocolate-brown crystals in matrix on this excellent specimen from the Joan Astor Collection.

Size: 4.5 x 4 x 3 cm.
Main crystal: 1.8 cm.
Found in 1994.

Col. Joan Astor.