Photos too dark and not in focus to tell anything,are the table facets abraded?
It's not hard for hobbyist,etc to re-cut most stones except diamonds.The people who robbed the vault probably have "underworld" connections...
https://www.antiquers.com/threads/identification-help-mexico-silver-necklace.43481/#post-1169096
The number is a tax number,here is another one with TO96......
Tiger's eye and probably black dyed travertine.
Looks like the security certificate is valid, try using this... https://www.925-1000.com/ Sometimes depending on your software they do not...
They didn't use one of these? https://www.buyemp.com/product/ring-cutter Every emergency room and clinic always had one on hand.
Mexican art glass opals
Flat plane carving,thousands of people have used the technique, hobbyist,etc. https://fanningsparks.com/flat-plane-carving-with-harley/
Looks like the bowl is Chinese fluorite.
I don't know where you live,but I Googled "opal cutters" and Midwest and came up with a name I recognized,he has been around for 40+ years and has...
The opal is not centered in the setting.Some setters say they must be tight and others say there must a little room for movement.Opal can develop...
Real for you,but most U.S. banks don't accept them.
Separate names with a comma.
