26Moz, +5g/t AuEq Gold, Silver, PGM Porphyry Exploration Target. First assays imminent., page-643

Bloody annoying when HC loses important images in a post. Posting again...

I was talking to a mate about the poor performance of the partial extraction in the assay method and how it appears to be undercalling the much higher partial extraction grades from the metallurgical testwork method (up to 360g/t). Worth repeating here maybe.

Basically the assay might be extracting precisely 5% of the metal from the sample every time which is why it can be used as an assay method because precision is critical for an assay method.

The experimental metallurgical extraction testwork is more accurate because it's recovering more gold but very imprecise because of the highly variable extraction efficiency, extracting maybe 0.1 - 95% of the metal from the sample. That's to be expected from an experimental method.

I referred to this in earlier threads as the extraction efficiency. The cumulative freq. chart for all extraction testwork drilling results from TE helps explain why I'm expecting the true grade to be much higher than what we've seen so far. Obviously this applies to all the metals, not just gold.