melanocerite
/mɛlənə(ʊ)ˈsɪərʌɪt/Mineralogy
noun
A translucent resinous fluosilicate of cerium and calcium occurring as black or brown tabular crystals of the trigonal system.
Origin
Late 19th century; earliest use found in American Naturalist. From melano- + cerite, after Danish melanocerit.