- Franckeite (Var: Potosiite), Franckeite, Jamesonite
- Small Cabinet, 8.2 x 4.4 x 2.1 cm
- San Jose Mine, Oruro City, Cercado Province, Oruro Department, Bolivia
From the find of 2004, this specimen hosts two rare sulfosalts. This specimen is a rare, superb, crystallized specimen of the triclinic lead, antimony, iron, tin sulfosalt Potosiite consisting of several, extremely rare, highly lustrous, heavily striated, tabular blades (some are twinned) of Potosiite measuring up to 9 mm sitting atop crystallized and the equally rare triclinic lead, tin, iron, antimony sulfosalt Franckeite. The piece has a small amount of associated acicular Jamesonite as well. The Potosiite has been positively identified through X-ray Diffraction.