Bournonite (“cogwheel”-esque twins)A hard to find "cogwheel" esque group of sharp, fairly thick, blocky modified twinned crystals of Bournonite with excellent luster and aesthetics. The piece would be classified as a large thumbnail small toenail and displays well from several angles (my favorite being the last picture). The stacked appearance of the crystals, combined with the bright metallic luster, makes this one of the more unique smaller Bournonites I have handled from this mine.

blue-green color “butterfly”-twinned crystals with tan Siderite and dark reddish-brown Sphalerite

The good news is that I directly obtained this specimen from the miner who collected it

The crystals are associated with minor Quartz and Pyrrhotite on the reverse side of the specimen

Specimen # AMAZWH111916

let alone the fact that the crystal stayed on matrix

and when it arrived

or a suite of Bolivian specimens

and you would be hard pressed to find better color Vauxite anywhere

which is impressive as most of the Ferberite twins are broken on one end

It hosts a few

Specimen # BOL711B222

Specimen # BOL711B64