Unique Vintage Inverted Square/ Diamond Shaped Silver Dangling Earrings w Stone

Unique, Vintage Inverted Square/ Diamond Shaped (Sterling?) Silver Dangling Earrings with Stone (Crystal?). Believe these are Sterling Silver as they tarnish but couldn't find any SS or 925 marking. Think the center stone is a crystal, not diamond. Lovely, unusual design piece. Great for any occasion- work/ school/ date/ etc.