- Cassiterite, Quartz, Siderite
- Miniature, 4.3 x 3.0 cm
- Viloco Mine (Araca mine), Loayza Province, La Paz Department, Bolivia
The great tin mines at Viloco (sometimes called Araca) have produced some of the most magnificent Cassiterite specimens extant. This particular specimen hosts several fine, sharp, highly lustrous, black-brown cyclic twinned crystals with gem Quartz crystals and tan Siderite "rosettes".