trying to id cultured pearl necklace mark

I picked up some lovely 18 inch, 6mm cultured pearls at the Goodwill the other day and I am having a hard time figuring out the mark/hallmark. The clasp is fancy gold filigree, with slider part has 14K and a diamond shape with a wide letter W in the center. I couldn't get a good close-up with the camera so I am enclosing a picture I drew of the mark. Thanks so much for your time.