RE:linked articleI've said before that I'm no geologist, but my take-away from that technical presentation is as follows:-
It would appear that the sum total of work done on AK11, since its discovery 47 years ago, appears to literally consist of one 'scratch' at the surface that;
(a) mis-identified the kimberlite facies
(b) gave its area as only 0.14Ha
(c) was not drilled.
We now know that it's about 18 times bigger (2.5Ha).
Furthermore, although the report says that microdiamond results were not to hand at the time of writing, we do know that they have proceeded to wide-diameter bulk sampling. I think that is a good reason to guess that the micro-diamond count was adequate or better.
Micro-diamonds are tiny specks that provide an early guide to likely grade. A quanitity of drillings, perhaps a couple of hundred kgs, are crushed and digested in various frightful acids and/or alkalis until the only stuff left is diamond and other inert substances. The diamond specks are then counted. The rule of thumb is that 1 micro-diamond per kg of original sample is considered worth following up on. More than one is better of course.