Vintage Sterling Silver Marcasite And Amethyst Ring Size 4.75-5 Hallmark 925

This is a gorgeous stamped Sterling ring in between 4.75-5, very close. Faceted oval Amethyst and sparkly Marcasite surrounding the stone. There’s a hallmark on the inside of the ring but I can’t quite make it out. Possibly Judith Jack? Back to back triangles with possible JJ inside.. This would make a lovely gift for anyone who loves to shine. Please take a good look at my pictures and let me know if you have any questions.