French 18ct Gold, Shamrock Enamel & Diamond Stick Pin, Irish Themed

A very unusual antique French 18ct gold stick pin with green enamel shamrock head with 2 small rose cut diamonds collet set, one to the centre and the other to a leaf edge. Picture 1 the green enamel base of the central leaf, it appears to have been touched up there leaving a microscopic chip, this cannot be seen in wear as in "if you can see it ,you are far to close". The yellow gold pin has a French standard mark for 18ct gold, (eagles head mark) and a makers mark which is worn. Period: 1880s to 1910s, suitable for tie, lapel, cravat etc. The case that it comes in is of that period but I doubt if it is the original case.