Definition of psilomelane in US English:

psilomelane

noun

Mineralogy
  • A hard black ore of manganese which consists of a mechanical mixture of manganese oxides and hydroxides, usually also containing barium and other metals.

Origin

Mid 19th century. From psilo- + ancient Greek μέλαν, neuter of μέλας black, after German Psilomelan, itself apparently after schwarzer Glaskopf.

Pronunciation

psilomelane

/ˌsʌɪlə(ʊ)məˈleɪn/