Rosell Minerales

 
 
You are in > Home > Minerals

Catálogo de minerales

RM2537   Cobaltite

Española, Brazil Lake occurrence, Foster, Sudbury District, Ontario, Canada

These cobaltite specimens from the Espanola area, Ontario, are a classic of Canadian mineralogy. They show brilliant cubic cobaltite crystals on a matrix with calcite. Good size for this locatlity. Sudbury District was a very active mining area and, in past times, one of the best places in the world for cobaltite specimens. However, even then, it was not easy to find these specimens on the market. It comes from the Joan Astor collection (Barcelona), with a handwritten label and another typewritten.


Size: 6 x 5.5 x 4.5 cm.
Main crystal: 8 mm.
Found in ±1975.

Col. J. Astor, Barcelona.
Classic locality
 

RM2137   Betafite (of Hogarth 1977), variety of Pyrochlore

Silver Crater Mine, Basin Property, Faraday Township, Hastings Co., Ontario, Canada

Group of interpenetrated betafite crystals of good size that show the most developed faces of the dodecahedron. Interesting crystallography. It is accompanied by zircon crystals. These mottled-brown isometric crystals are from the well-known Silver Crater Mine at Bancroft. This is an excellent and uncommon example, today. Most specimens of this quality came out in the 1950s, during the active mining period. An old, classic and essential piece in any collection. This specimen bears the label of Tysons', a Canadian mineral dealer.
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: 4 x 3 x 2.5 cm.
Main crystal: 2.4 x 2.4 cm

Presents radioactive activity.


 
1