Pearl and Sterling Silver necklace with unknown stamp

[vcamp11]

I have an approx. 20 year old pearl necklace with an elegant little clasp made from sterling silver. I have had a friend in the jeweling business look at it but he does not recognise the stamp either. The stamp shows clearly a 925 symbol and a W over G that I have not previously encountered. would anyone be able to identify it? it would be greatly appreciated!