ok fair. I didn't fully understand the point and wasn't aware that gold was, say, denser than lead. (not a metallurgist, just a biochemist), and I was fixated

ok fair. I didn't fully understand the point and wasn't aware that gold was, say, denser than lead. (not a metallurgist, just a biochemist), and I was fixated on the deficiency of point #1. Thanks for pointing it out. In either case, verifability of gold is thus a product of TWO easily assessed properties, not just one.