The $1000 margin is Australian currency Its Based on 2.5 grams a...

The $1000 margin is Australian currency
Its Based on 2.5 grams a tonne recovered .
Iron bark average grade is around 3.6 grams a tonne so guessing should be around 3 grams a tonne recovered if you take into account dilution and processing losses .
At 3.5 grams recovered a tonne the margin increases an extra $400 .00
However for me , I feel best to be conservative as have been burnt so many times where grade under calls on the ROM pad , with companies I have invested in .
Also we do not know the actual strip ratio , I used 10:1 it could be higher so another reason to be conservative , ie if we knew the OVM per 10 meters over 120 meters it would also be easier to calculate , as would knowing when they change over to UG mining I was guessing 120 meters , as would knowing the rock competency , I just average pit wall angles at 45 degrees for both oxide and fresh rock , which is hardly professional .
Also once you go out of oxide into transition / sap rock into fresh rock the SG changes , I just used an SG of 2.3 it will be higher than that in fresh rock probably up around 3 .