"Swiss bank in a box"

[Ken Brown]

Though as a matter of off-topic actual fact, no gold (maybe outside a
few labs that are trying hard) is likely to be pure enough not to be
traceable. As far as I know archaeologists & art historians (& I assume
police) have been matching gold artefacts to their sources for some time
now. Not as easy as copper (or oil - tax people like being able to trace
oil to wells) but doable.

Doesn't alter Tim's point that you can obscure the origins my mixing
gold from different places of course. Not, I imagine, something that
anyone actually ever does, but it would obviously work.

Googling for "gold isotope provenance" got me 911 hits. 

Ken Brown

Eric Cordian wrote:
> 
> Tim wrote:
> 
> > ...gold can be melted and all traces of origin lost, save for some
> > expensive tinkering with isotopic ratios, maybe.
> 
> Gold, last I looked, had a single stable isotope which accounted for 100%
> of its natural abundance.  79-Au-197.
> 
> One piece of pure stable gold is indistinguishable from another.
> 
> So if your gold is pure and isn't radioactive, it hasn't been tagged by
> isotopic ratio tweeks.