A striking all sapphire geometric Art Deco pin conversion. 
We have used the pin to form the jump ring, to preserve the (feint) French hallmark. 
 
Also works as an extender with dog clip clipped through the sapphire circle. 
 
Stamped and tested as 18ct gold
Weight approx 0.56g 
Total drop approx 17mm
Width approx 10mm
Excellent antique condition