...I've got two GGs in the cupboard... one has the Gortex "diamond shaped" logo in between GG and Made in China and some other waffle on the label. The other jacket has similar label on it, but has lots of words about Gortex embossed on the material. So that label isnt great, but that doesn't mean this isn't real, but doesn't confirm it either.
Send pics to GG might be an option... and the advice above is good!