I only have one gold and onyx ring bought in Gold Street in Muharraq 1967. It was for a special reason to naively wear/carry something of instant value in case I found myself in difficult territory at a time when the UK was extracting itself from Khormaksar Aden, now part of the Yemen. We were flying lots of stuff in C130's out with the possibility of being shot at and forced landing where local people were perceived to mutilate their captives. The idea was to buy time/release/retention of body parts etc. As I said, naive, but I was young.
When bought, there was no hallmark. It was priced by weight on a scale. A couple of years ago I had the ring assayed and hallmarked so that I could hand the ring to my son in future. It is technically 21ct gold but in the UK no such mark exists, so I had to accept the London 18ct mark.
I rarely wear it because a ring is dangerous if caught on a door handle or a tool or some other obstruction.
Clive