semiprecious
adjective [ before noun ] uk/ˌsem.iˈpreʃ.əs/ us/ˌsem.iˈpreʃ.əs/
（宝石）次珍贵的;半宝石的
A semiprecious stone is one that is used for making jewellery but is not extremely valuable.
Jade and turquoise are semiprecious stones. 玉和绿松石是半宝石。