Travelling with a friend a couple of years ago in the Brazilian hinterland, I had the opportunity to photograph diamond parcels from several locations. This photo was captured in Andaraí, Chapada Diamantina, Bahia.
The region is a classical diamond producing area that has seen its heyday several decades ago, especially during WW II; current diamond garimpo is very limited. Diamonds in this area are characterised by the presence of carbonado (a variety of microcristalline diamond; a dark rock made of tiny diamond crystals, its origin being speculated as resulting from a meteorite impact), a feature in common with Central African Republic diamonds.
sinese.org 
Although many of the diamonds shown have considerable clarity, they lack desirable colour. Is there possibility of reopening mines at Bahia?
Thank you for commenting. I don’t think the reopening of large-scale diamond mining likely in this area. Alluvial diamonds (including carbonados) and their (conglomerate) sources are present but the area is now under special environmental protection. Only very small-scale artisanal diggings are allowed (should I say tolerated?). You can still find diamonds being traded in Lençóis and elsewhere but on very limited scale (unlike say 30 years ago, when the area was buzzy).
Some of these diamonds come from other Brazilian regions (e.g. Piauí); that shouldn’t be seen as a surprise as I have recently seen and photographed a Zimbabwean parcel in Diamantina, MG (Brazil). That parcel must have an interesting story.