Gemstory Co., Ltd. ( http://www.gemstory.co.jp/ ) conducted a discoloration prevention test of Ethiopian Opal coated with Sweat Barrier. A sure test for opal experts. The sweat barrier successfully prevented discoloration! This video is posted with permission from Gem Story Co., Ltd.
![エチオピアオパールの変色を防止](http://nickel-allergy.com/cdn/shop/articles/opal.jpg?v=1653984578&width=1100)