Wangfujing is a big shopping mall, so it is unlikely to be faked. If you are afraid of buying fakes, you can take them to an appraisal agency for appraisal. There is a jewelry appraisal agency near Wangfujing, Nonglinxia Road, but the appraisal costs money, and the appraisal is generally true. I just can't see whether those refractive indexes and a lot of data are good or not.