Vintage Art Deco style stamped A925 sterling silver amethyst ring sz 7.5-7.75

Vintage Art Deco style stamped A925 sterling silver amethyst ring sz 7.5-7.75. Striking ring with sparkling marcasite stones surrounding what I believe are highly faceted amethyst and pear-shaped peridot stones. I am not a gemologist, but am making an educated guess based on a longstanding interest in gemstones. Sits between size 7.5 and 7.75 on my ring sizer. Good condition. Light wear. Aging/patination to metal. Marcasite appears intact. Amethyst could use a gentle clean. Please refer to photos for additional condition details. 3C