Vintage collar studs

Nice pair of butterfly collar studs. They are to wear on detachable collars. Victorian/Edwardian wear and clergy/clerical collars. Neat item and something unique to gift someone that has everything! Or is into vintage and antique clothing and items to collect. These could be reimagined and used as cufflinks maybe? I think the material is enamel or Bakelite. Some signs of wear due to age and use. One has a sought reddish ring around and not sure if it was original or from age. They seem quite sturdy but would recommend taking care when opening and closing each side and if they bend just gently bend back! Please see photos for the best description and any questions please ask thank you