- Ferberite pseudo. After Scheelite
- Small Cabinet, 6.9 x 5.4 x 3.6 cm
- Bugarama, Rusizi District, Western Province, Rwanda
An interesting partial pseudomorph from an unusual locality! The beauty and true story of this mostly black small cabinet piece lies below the surface! The rough shape of a large, partial scheelite crystal is incompletely replaced by black, granular ferberite on the exterior and examination of two exposed surfaces show "islands" or domains of yellow to gray, translucent to gemmy scheelite on the interior transected by thin veinlets of ferberite. This piece represents a snapshot in time of a pseudomorph process where iron tungstate is replacing calcium tungstate. This locality is part of a large tungsten province that straddles the triple junction of the Rwanda-Uganda-Congo borders. Much of the tungsten mining in the Rwanda portion is very labor intensive with little mechanized ming. A great piece for the pseudomorph collector and those that appreciate ore textures! An Apple Valley Minerals Ltd. (Sal Avella and Fred Corcoran) label accompanies the piece.