Siderite, Sphalerite
Aggenys Mine, Northern Cape Province, South Africa
Small Cabinet, 8.4 x 7.9 x 5.7 cm
From a small find that was brought out at Munich in 2006, these are very unusual crystals in that they are hollow casts after calcite, and the coating is a mixture of sphalerite and siderite. They have been extensively analyzed in South Africa, to come up with this conclusion, by Bruce Cairncross and others. So far as I am aware, this is a first. This has good 3-dimensional form, a good surface shimmer (almost metallic), and no damage except to the periphery where you can see into the hollow casts. Ex. Charlie Key.