Jamesite is an exceedingly rare lead zinc iron arsenate. I have personally nevert seen another for sale, but I am told that this IS indeed an excellent specimen for the species by somebody who has. This piece features eye-visible (sub-mm) red crystals in a rich zone in the upper-right of the matrix. It's easy to spot and has also been independently analyzed by Joef Vajdak in the Czech Republic and by Marcus Origlieri at the Univerity of Arizona. Note that in the reference book, TSUMEB II by Dr. Georg Gebhard, the species is designated "RRR," i.e. "Extremely rare single occurrence with less than 10 specimens known" (obviously not accounting for later trims). 3 x 3 x 2.5 cm