Ann: RIO: Rio Tinto reveals maiden Resource at Winu and new disc, page-36

Then why would RIO be spending $millions drilling Calibre 24/7 @moment, if they already know it's a gold dominant deposit? You think they're wasting time & money for nothing?
Of course gold's it's in it's development strategy

Calibre will be profitable & it will be mined, that's a certainty. And Calibre is only 1 of numerous deposits on JV ground

The delays that RIO have projected on their Mongolian copper/gold project sh#t show, they won't turn a profit until around Y2035. With their Paterson plans for a Pilbara Iron Ore-like large scale operation of copper/gold, they'll turnover massive profits in a short time, and grades won't be the dominant factor