- Acanthite, Polybasite
- San Juan de Rayas Mine (Rayas Mine; Reyes Mine), Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico
- Small Cabinet, 5.5 x 4.3 x 2.7 cm
This is an important silver species specimen with excellent aesthetics and very rich masses of sharp polybasite crystals. The bladed polybasites form clusters atop a natural pedestal of silver-rich matrix, and atop each of the polybasite crystals there are sharp outgrowths of brilliantly metallic, pseudocubic, little acanthite crystals - mostly 1 mm in size but forming larger clusters. The polybasites, as do so many from here, have some slight coating of iridescent material or alteration. The stark contrast between these pseudocubic-blocked towers and the bladed polybasite under them is really interesting. Ex. Harold Urish Collection.