RE: Gold Concentrate8 Jan 2021 10:28
The grades quoted in drill results are the grades within those quartz veins, i.e. when mineralisation has been hit, so the host rock is already excluded. You're right in the sense that there can be a lot of variation between different grades, but it's illogical to think that a series of 0.5-1.5 g/t quartz veins suddenly become 20 g/t when taking a bulk sample.
The 20.7 g/t refers specifically to a concentrated product at the end of a process designed to extract gold from the input sample, which is obviously going to be a lower concentration.