Vintage Marcasite silver 925 & Onyx Ring

Selling a vintage ring featuring marcasite stones and a central onyx stone. It's a unique and eye-catching piece! Some stones out it’s replaceable I think 🤔. Not sure about size side I haven’t got to check my finger size cause after pregnancy it’s been changed. If possible I can measure from scale. Let me know thank you 🙏🏻