The old timers extracted 124,000Oz ($A334Million today)of gold at a bonanza grade of 34.1g/t gold (just over 1Oz /tonne in the old money) because of these high stibnite/antimony enriched zones at Big River below.
You can see the grey stibnite in both the Alexander River and Fosterville drill cores.
These jewelry boxes form not in the main structures, as per Dr Hinnigh's comments in the New Found Gold videos, but just off the main lodes where vlugs(holes) and lower pressure rocks allow for the hydrothermal fluid to trap and crystalise the gold into bonanza grade pockets, together with the stibnite/antimony.
These jewelry boxes form bw 800metres and 1,300metres from surface in these epizonal gold-rich zones.
this is why Siren's most recent visible bonanza grade gold was also its deepest hole to date.....you normally cannot see 1-8g/t gold with the naked eye. To see visible gold without a magnifying glass, as per below, it has to be over 25-30g/t gold in that core.
As per Fosterville and Queensway, it is the collection of these types of drill cores that built up and bank the jewelry boxes like the Swan Zone at Fosterville and Keats and Appleton zones at Queensway.
The beauty about Siren Gold's assets in NZ is that even with that they have already discovered, eg no jewelry box yet, their All In Sustainable Costs are only ~$A900-$A950/Oz...
The jewelry box Swan Zone has allowed the Fosterville gold mine's All In Sustainable Costs to fall to an industry low $US312/Oz ($A415/oz) and quadripled the annual gold ounces produced each year compared to pre Swan Zone discovery.
