The owner of the Alnwick-based Bari Tea Brewery, Caroline Stewart, says: "Green teas are generally unoxidised
or have undergone just a small amount of oxidisation.
1 for gold and other unoxidised
metals to near unity for ceramics.
Finely crushed grains of goethite within the spoil (<3mm in diameter) appear to contain unoxidised
cores of chalcopyrite, suggesting it was this fraction of the ore that was being sought and crushed, perhaps to release copper in the form of disseminated malachite and copper oxide; minerals that could much more easily be smelted.
ASS extended to the bottom of the sampled profile, and had a neutral pH and a progressively more reducing state.
400 metres of the 700 metre programme have been completed to date, with all holes intersecting mineralization, as targeted, of dominantly malachite and mixed copper sulphides in the oxidised zone and bornite-chalcopyrite-chalcocite-malachite in the unoxidised
Complex behaviour patterns are favoured under dysaerobic bottom conditions, where unoxidised
organic matter accumulates near the water-substrate interface.
All samples were in the reduced unoxidised
zone as evidenced by the visual lack of iron and jarosite precipitates, except McLeods Creek A which had experienced some oxidation and contained iron oxide segregations around vacant root channels.
Gold mineralisation is known to extend into the underlying unoxidised
rocks and this has the potential to host substantial additional sulphide resources.
sulfidic materials are often referred to as potential ASS.
Since shafts are often sunk beyond the limits of the ore zone and most of the production drifts may be driven below the orebody, the waste rock may be less sulphurous, even though all of the material could be unoxidised