The most interesting part for me is : The nature of the...

The most interesting part for me is :

The nature of the mineralisation is currently unknown. A finely-disseminated, unidentified silver-gold mineral, possibly a sulphide, comprising around 0.5% of the rock mass has been observed in the majority of chip samples, but it is not clear if this mineral is directly linked with the precious metals recovered from the samples. There is no visible sign of hydrothermal alteration in the rock mass.

and

The analytical method used for the three Três Estados assays was routine fire assay with a lead collector on a 25g sub-sample following a proprietary pre-leach step and precipitation of precious metals with aluminium and sodium hydroxide.