The National Association of Jewelry Appraisers (NAJA) - is the only appraisal society exclusively for gems and jewelry appraisers only. www.najaappraisers.org

The American Society of Appraisers (ASA) - is an appraisal organization representing all of the disciplines of appraisal specialists.  ASA is dedicated to the benefit of the appraisal profession. www.appraisers.org

Federal Trade Commission (FTC) www.ftc.gov (enter jewelry in the search panel for various helpful links).

Gemological Institute of America (GIA) was established in 1931 and is the worlds largest and most respected nonprofit institute of gemological research and education. www.gia.edu

Lightning Ridge Opal – miner, cutter, supplier of opal www.opalguy.com