Polybasite (pseudomorph after Acanthite)

Here we have a wonderful cabinet sized display specimen featuring fine quality, sharp, dark grey colored, pseudo-hexagonal crystals of Polybasite on all sides. At first glance, the underlying matrix appears to be crystals of Acanthite, but upon close inspection, you can see hundreds of tiny Polybasite crystals on the surface, which combined with the somewhat skeletal nature of the Acanthites makes be believe that these could actually be pseudomorphs of Polybasite after Acanthite. This is honestly the first time I’ve seen something like this from any locality in Mexico. I remember seeing some pseudomorphs of Polybasite replacing Pyrargyrite years ago from Guanajuato, but NEVER Polybasite after Acanthite.

As mentioned, you need to look closely at the piece, and we’ve taken some micro photos to better illustrate that there are many tiny Polybasite crystals all over the piece, not the main group, which measures 2.0 cm across. A small coating of white Calcite can be seen in certain areas for a nice contrast of color. A very special and unique specimen that would make for a fantastic addition to any suite of sulfides/sulfosalts, silver-bearing minerals or minerals from Mexico.

Specimen #WWMIX82106