The Chimbongo (aka Chibongo)- Luembe river, NE Angola – alluvial diamond deposits have been worked for several decades. The area is characterised by a close to 3 diamonds per carat diamond size and a 150-200 USD/ct price range.
The Luembe river, an affluent of the Kasai (itself a tributary of the mighty Congo river) structures the mineralisation (present in the gravels of the river bottom and in its alluvial plains but also in earlier conglomerates – the cretacic Calonda Formation – aka Cuango or Kwango Formation).
Luxilo, located north of N’Zargi, is the most important locality nearby and was formerly the base camp of the Chimbongo mining operations.
The blog has a new photo gallery about this deposit. Other galleries will follow suit – keep checking.