The Sapphire is likely to be synthetic.
The Necklace, as seen in one photo, is not included but offered up for sale too. Art Deco set with Madeira Citrines.
French Hallmark for 18ct Gold
Size: 15mm x 11mm
Ring size : 55
Weight: 7g
Comes with a Warranty Invoice and in a new velvet box.
Free postage in France.