look at the website nadl, page-7

Seals
if your saying is true that a lot of low fluorescence stones could not be picked up under X-ray sorting by RIO, that means there still a lot of hidden treasures in the wastes from previous 9 pipes that these wastes were used to reclaim land or dumped in the remote areas. Could these waste been recovered to reprocess under optical and physical sorting by present Management of NAD? will that be economically justified in doing so? Guess Mr. Reddicliff should have the answer to this!