Correct me if I'm wrong but it seems to me that the figure of 10 million tons was tossed about as the number required to justify a mine on Noront's property. That takes into account the fact that not all mineralization will be as rich as hole #5 hit.  Of course even 7 million is still a guess as not enough drilling has been done to calculate 'proven' reserves.

The great thing about McFauld Lake area is that it's pretty obvious there will be other deposits found and in that case the infrastructure costs can be spread out over several mining sites. Quite likely that even 4 or 5 million tons will result in viable mine if more than one deposit is proven. Noront alone are pretty confident they will turn up more deposits on their properties.