In order to be called Champagne it has to come from the Champagne region of France much like Scotch has to come from certain areas of Scotland and how Bourbon has its own set of requirements (seemingly only applying to Canada and the United States).

My suggestion: buy your wife or girlfriend something more valuable than jewelry such as self-defense classes or maybe driving lessons on a track. Despite the short duration of the lessons, it'll still be worth more than a diamond ring in terms of pragmatic value.