Vintage/Antique 10k Gold & White Opal Stick Pin with Filigree Border

This is a beautiful vintage or antique 10k gold stick pin with what appears to be a white opal. The stone is surrounded by a simple filigree border. The pin is not marked, and there are some dark spots on the top. Overall, the piece is in very great shape. When electronically tested, the gold tested consistently as 10k. The opal has not been professionally confirmed. Weighs about 0.9 grams. Length is about 2.16in.