https://www.gia.edu/gems-gemology/spring-2019-microworld-native-copper-inclusions-in-indonesian-purple-chalcedony
Native Copper Inclusions in Indonesian Purple Chalcedony | Gems & Gemology
Indonesian purple chalcedony containing interesting native copper inclusions is a first for the Carlsbad lab.
native copperin indonesianpurple chalcedonyinclusionsgems