https://art-shkatulka.com/2020/03/05/demi-fine-jewelry-%d0%b8%d0%bb%d0%b8-%d1%82%d0%be%d0%bd%d0%ba%d0%be%d1%81%d1%82%d0%b8-%d1%8e%d0%b2%d0%b5%d0%bb%d0%b8%d1%80%d0%bd%d0%be%d0%b9-%d1%82%d0%b5%d1%80%d0%bc%d0%b8%d0%bd%d0%be%d0%bb%d0%be/
Demi-fine jewelry, или тонкости ювелирной терминологии