Tailing Recoveries Prove Profitable For North Australian

North Australian Diamonds Limited recently announced that some five percent of the 12,000 carats of tailing that have been recovered from the Merlin diamond field are yellow. The tailings material, from which the diamonds were recovered, has previously undergone multiple passes through concentrating cyclones and x-ray sorters.

These recoveries demonstrate that the previous operations not only discarded high value non-fluorescing diamonds but also a high proportion of smaller near gem and industrial quality diamonds. The largest diamond to have been recovered at the site is a clear white 14.21 carat gem quality stone. Two additional large near gem stone quality stones of 10.97 and 10.27 carats have also been recovered. The largest yellow diamond recovered is 4.33 carats and near gem quality. These large diamonds are a characteristic of the site.

Many of the yellow diamonds are fancy yellow and have been valued at $1,454 per carat, though two of the most valuable stones were valued at $4,500.

The valuation of both gem and near gem white diamonds achieved an average value of $109 per carat, but includes a number of gem quality stones valued in excess of $1,000 per carat. A previously reported 14.21carat white gem quality diamond was valued at $1,815 per carat.

The combined average value for the yellow, white, and brown gem quality and near gem quality diamonds, which represents approximately two-thirds of the valuation diamond parcel from the tails, is $140 per carat. The relative proportions of the various categories recovered from the sort house tails is not representative of ‘run of mine’.