These specimens came out of this mine two years ago, and are among some of my favorite "new finds" from Bolivia. This piece features a good sized, sharp, very dark silvery "brass" colored, twinned crystal of the rare copper iron tin sulfide Stannite with is associated with a greyish-brown color tabular crystal of Andorite on prismatic grey Zinkenite matrix. There were only a handful of these specimens, and for my money, they are superior to most Stannite from China because the Chinese crystals are sometimes composite crystal groups consisting of many smaller crystals to form a larger aggregate, and nowhere else besides this find have I ever seen twinned Stannite crystals like these. To find these specimens on matrix is next to impossible, as well over 95% of them were floaters off matrix. This is a very choice specimen and a great quality piece for what it is. Ex. Brian Kosnar.