Ettringite on Matrix
N'Chwaning Mines, Kuruman, Kalahari Manganese Fields, Northern Cape Province, South Africa
Named for Ettringen, Germany after the discovery of its type locality in 1874, ettringite is a sulfate which originally formed as a precipitate from hydrothermal solutions. This specimen is from a small find at this famous old South African mine. Usually specimens from this region are formed of free-standing crystals without matrix. However, this particular specimen is unique in that it features translucent yellow-green crystals, measuring up to ¾ of an inch, on a dramatic black matrix covered with drusy micro-crystals. The luster shimmers and the hue of the crystals has a touch of golden yellow.
Measures 2 3/8 x 2 x 1 in.