...and that's just the concentrated ore. It doesn't consider all the surrounding rock required to be moved for a drift or open cut. This rock needs to be crushed... then ball milled into a powder as fine as baby powder... then pumped into vats of sodium cyanide... then activated carbon baths, then electrolysis, then primary smelting BEFORE its transported to the Perth mint for refining.
That's 34.8 g/ton. Most mines now probably haven't got ore grades any better than 5 - 10 g/ton, and that may be too generous. So that pile of ore you are looking at to get your 30g bar of gold is probably a lot closer to 3 - 6 tons in size. I've read of ore grades of 240g/ton, but obviously that was way back and the easy stuff has long gone. Bill
It don't look like nearly a ton of ore sitting there. It looks like a small stone being weighed on old fashioned home scales.
I think the pic is mis labeled. Looking at the piddly wires that block of a sample not the 860kg. But you get the idea of the work that goes into getting this precious metal.
That grain of rice is supposed to represent the tiny amount of gold in the large deposit. Nothing is to scale , just an example to highlight the work required.