Gold - the last man standing, page-30

I understand your point and know what you are trying to say but you need to take into account human sentiment and the human condition.
Gold is valuable simply because we consider it to be valuable. Nothing more and nothing less.
It would appear that something has to be regarded as such and Gold is what humans have settled upon.
It could have been lead, it could have been shells, it could have been printed paper but in the end it is Gold.
It has stood the test of time.
Speaking of which (and with no disrespect) Your wife will be most unlikely to retain these qualities in 50 years time while Gold will still maintain its intrinsic value. No offence intended.