allopalladium
/ˌaləpəˈleɪdɪəm/Mineralogy. Now rare
noun
A silver-grey mineral containing palladium and other elements, originally thought to be an impure allotrope of palladium and now identified with stibiopalladinite.
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From allo- + palladium.