Siderite, Sphalerite
Aggenys Mine, Northern Cape Province, South Africa
Miniature, 4.2 x 3.4 x 2.1 cm
A fascinating and striking pseudomorph miniature specimen from a small find that was brought out at Munich in 2006. These very unusual, barrel-shaped crystals are actually epimorphs, i.e. casts after calcite crystals, which have been dissolved away. Microprobe analysis in South Africa by Bruce Cairncross and others shows that the shimmering, metallic-like coating is a mixture of siderite and sphalerite. The piece is very light weight for its size and, in fact, the cast is hollow. Complete all-around and pristine.