RE: Ongoing5 May 2021 14:23
Hi Echo!
Commerciality essentially equals:
As I understand it, (Quantity (volume / tonnage) of kimberlite (and breccia) x grade (carats per hundred tonne) x diamond value per carat) - costs to mine and process.
So what do we know so far?
1. Kimberlite quantity - The River Pipe measured 80m x 40m at surface (which, as an oval = 0.25 hectares). This new pipe, as so far defined measures 75m along strike, and, according to the company, is currently is about the same size as the River Pipe. So call it another 0.25 hectares.
That compares favourably with Sugarbird (0.5 hectares) and Marsfontein (0.4 hectares). Both of these blows / pipes were commercial and were mined out. Marsfontein (only 3.5km away from the new discovery) was of course a fabulous success.
And, importantly, it seems there may be more kimberlite to come once they manage to get the drill down into the ravine, as James Campbell clearly expects the two pipes (only 100m apart now) to join together into one.
The implication of that is that the pipe will turn out to be more than 1 hectare in size.
2. Grade - the dyke system consistently grades at 60 cpht (46 - 74cpht). I'd expect that number to be a minimum figure for a blow. Remember, we already know concretely that the River Pipe contains not only plentiful diamond indicators, but also diamonds, as there were 11 gemstones in the drill samples (a remarkable occurrence).
3. Price per carat - along the dyke the price per carat is USD 120 – 220/ct. Again, I'd hope that the numbers for a blow are bigger, especially if any large stones are found, like at Marsfontein.
4. Cost of production - I can't see any reason why it should be particularly costly to mine the River Pipe. And there is an existing diamond mine on care and maintenance only 15km away.
All in all, that adds up to a clear picture of a commercial find to me. IMO, the question is more, do we have a SugarBird (i.e. a decently profitable proposition), or do we have a Marsfontein or better (i.e. a bonanza proposition)?