Noun
langbanite (uncountable)
A black, trigonal, sub-metallic mineral with the chemical formula of
M
n
4
2
+
M
n
9
3
+
S
b
5
+
O
16
(
S
i
O
4
)
{\displaystyle Mn_{4}{^{2}}^{+}Mn_{9}{^{3}}^{+}Sb{^{5}}^{+}O_{16}(SiO_{4})}
.