10K with ADL and 10K with GTA or GTR marked gold rings

by Connie
(Camden, TN. USA)

Hi,

I have 2 gold rings with genuine blue Topaz stones each.
One ring is marked 10K with ADL next to it. I heard it meant it is French. Not sure though.

The other is marked 10K embossed on one side and GTA or GTR on the other side of the stone (also embossed).

Can anyone tell me anything about these marks?
Thanks in advance!

Connie