bars that size need ultrasound for sure.The 2019 audit by the RBA of their gold holdings with the BOE appears to be a random selection of bars which are checked against recorded serial numbers, mint branding and weight...Would be interesting if the RBA audit team had / will take a XRF in with them to check a few bars etc....
in a secret fractional reserve lending scheme?
.
It all seems somewhat "pathetic" to me..... https://www.rba.gov.au/qa/gold-holding.html