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.
RE: GoldCash