JRB02 Ferberite with Jeromite on Quartz
Kami Mine, Ayopaya Prov., Cochabamba Dept., Bolivia
8.1x 7.0x 6.2 cm
$295
A beautiful specimen with a group of lustrous black ferberite a contrasting jeromite on quartz. The "jeromite" is not actually a mineral-- it is an arsenic, selenium, sulfur glass that lacks a definite crystal structure (hence the "glass" term) best known from this mine. In the past, I saw small single quartz crystals coated with this orange-red material, but this discovery is the first time that I have seen such rich examples. There are some rough areas, still a nice example from the find.