Have a look at https://www.goldmoney.com/w/n0t10b
They do something similar. Except in their case you buy physical gold which has been digitised.
Basically the concept is every goldgram you buy gives you title to real gold held in a vault.
Well established company with a good track record.
EDIT: sorry voted for my own post by mistake, still new here.
Thank you for your reply, I'm new here too and yours is my first on steemit. I'll look at that site.
So they hold the gold for you but they basically are a bank for gold if I understood.
Not exactly a bank.
Their big break through is to have a one- to-one mapping between a digidtal goldgram and an actual gram of real gold, as well as passing the ownership of the actual gram of gold to you when you buy the digital goldgram.
But I'm sure they explain it better on their website.