Ann: Eastern Mafic Hits Massive Sulphides, page-76

Chalco has about 34% Cu. Pentlandite has about 36% Ni. So do the math - how much of either do you need to give grades of 1% Ni and %1% Cu? Answer - about 3% of each.

So the core can be 94% pyrrhotite and still give reasonable numbers if there’s 6% chalco and pentlandite. If the sulphides are fine grained then I defy anyone to point out the 3% pentlandite from the pyrite and pyrrhotite with confidence with the naked eye and without thin sections.

But as always assays are king. There’s a lot of barren massive sulphide in the world. until the numbers are in all this debate about who can see what in sulphide is academic.