- Stannite, Andorite
- Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosi Department, Bolivia
- Thumbnail, 2.4 x 1.5 x 1.5 cm
A superb and aesthetic sulfide combination thumbnail specimen from the famous Siglo XX Mine at Llallagua, Bolivia. A sharp, lustrous, doubly terminated stannite crystal is jauntily perched upright on the side of a plate of sloping, lustrous, dark gray, acicular andorite crystals. Another stannite crystal is hidden below the andorite plate. Ex. Ed Ruggiero Collection, who purchased this piece from Pala Properties in 1975. This was and is an outstanding thumbnail for the two species.