1. Tested by China Geo University (Beijing) and Peking University, these two institutions belong to the national inspection authorities and can issue "Amber (Lanpo)" certificates to Mexican or Dominican Lanpo.
2. Conduct testing in some professional jewelry appraisal institutions, such as GIA (American Gemological Society), FGA (British Gemological Society) or GAC (China Jewelry and Jade Jewelry Industry Association). These institutions have strict appraisal standards and procedures, which can accurately identify gems and issue corresponding certificates.
It should be noted that the above institutions are not necessarily located in Hangzhou. You can check their specific information through the internet, or consult the local jewelry appraisal agency to get more accurate information.