Ferberite (rare doubly terminated twin) on matrix!A VERY rarely seen Ferberite twin on matrix from Tasna. Often, the Ferberites from Tasna are not found on matrix as they are heavy in nature and the brittleness of the species causes it to fall off the host rock in the blast during mining operations. This specimen is not only an impressive, and dramatically aesthetic matrix piece, but the Ferberite twin is DOUBLY TERMINATED, which is only seen in a very small percentage of pieces from Tasna. I

Specimen # BOL711B122

especially in such amazing condition

The “cogwheel” is essentially undamaged

No damage to the Brookites and it's not very often that one finds such superb eye-catching examples of the species like this in near full-size cabinet display specimens

or a collector of fine quality sulfides/sulfosalt display specimens

Perhaps the most interesting aspect of the piece is the fact that one side has near full coverage of Rhodochrosite

Federico Ahlfeld

The crystals on this specimen are sharp

This specimen was collected in 2000

It is one of the better crystals of this rare material that I have handled and would make a great addition to a thumbnail suite

Finding a fine quality "cogwheel" such as this on matrix from Machacamarca is not common

and well crystallized pieces ON MATRIX like this are few and far between from any locality