14k gold diamond and emerald stick pin

14k gold diamond and emerald stick pin with one hallmark. Picked it up at a recent estate auction. I'm new to antique jewelry and not sure what I have here. I believe the hallmark is left facing Mercury which would make it from France for export. But that's just my best guess and would welcome information from those with more experience in these matters. I was surprised that there was only one hallmark. Comments welcomed. Thanks.