METATORBERNITE
Metatorbernite is a hydrous copper uranyl phosphate mineral - Cu(UO2)2(PO4)2·8H2O.
It has a nonmetallic luster, deep green color, light green streak, is fairly
soft (H=2.5), typically has tabular crystals forming closely-packed clusters, and
is radioactive. This mineral is principally valued as collector specimens
and not as an ore mineral of uranium. Metatorbernite forms by partial
dehydration of torbernite (Cu(UO2)2(PO4)2·10H2O),
which in turn forms as a weathering product in U-rich rocks.
Metatorbernite plate, very likely from the famous uranium deposits
at the Musonoi Mine, just west of Kolwezi, Shaba Crescent, southern Zaire
("D.R. Congo"). Several areas in Africa have high
concentrations of uranium. Africa was the source of uranium for Madame
Curie & Pierre Curie's early investigations into radiation & for
America's first atomic bombs (CM public display, Carnegie Museum of Natural
History, Pittsburgh, Pennsylvania, USA).
For more info. on uranium minerals in southern Zaire,
see Gauthier et al. (1989, The
uranium deposits of the Shaba region, Zaire, Mineralogical Record 20:
265-288.
Metatorbernite from Bois-Noirs, Loire Valley, France (Colorado
School of Mines Geology Museum public display, Golden, Colorado, USA).