Vintage Sterling Silver And Marcasite With Ruby? Stones Snake Pin

I inspected this piece with a loupe to be sure no stones were missing and I did not see any. Stamped 925 on back I just loved this as I’ve had it awhile I loved to pin it to my bag or front Jean pocket there are Marcasite stones and I guess maybe Ruby stones? For the snake eyes. I’m not sure what they are really they look like Ruby Measurements are shown in above photo