A very aesthetic stalactitic specimen formed by a rich group of metatorbernite crystals. They present polysynthetic and echeloned growth of well-defined tetragonal crystals, with the characteristic green color. Under LW-UV we can observe the presence of a greenish-yellow intense fluorescence that indicates the presence of other species. SEM-EDS analysis have characterized this species as meta-autunite. We can say that the metatorbernite species is replacing the meta-autunite, as we can observe as a color gradation in some tabular crystals or in fresh fracture. This specimen come from late 90's finds in this classic French mine. Ex-col. A. Pouget.

Both, meta-autunite and metatorbernite, are dehydrated phases of the autunite and torbernite. The loss of water molecules, those are present in the crystal structure of these species, is a common fact when the specimen is extracted from the mine.

Size: 6.2 x 3.5 x 2.5 cm.
Found in ca. 1997.

Especies analizadas/Analyzed species
Fluorescent under long wave UV