Clasp is marked 950 the tag PT950 and other side Tiffany & Co Diamonds look authentic. No Markings on letter J Not selling as Tiffany & Co selling as a diamond small letter J. There are no markings on J so that's why I'm confused a small corrosion mark on clasp is also confusing. Flaw is the clasp doesn't look like it goes into the hole all the way probably wouldn't fall off, could potentially if snagged on something. Shows some wear. Always open to offers!