I'm pretty sure this gorgeous glowy flower is French, though it doesn't bear any marks to prove that, it just has the look and finish of the early 2oth century French pins that we love. 
 
We have converted it from a stick pin, adding a 5mm recycled gold jump ring. 
 
Tested as 18ct gold 
Weight approx 0.81g
Diamond tested as natural, earth mined diamond 
Total drop approx 18mm
Width approx 12mm
Excellent antique condition