allochromatic
/ˌalə(ʊ)krə(ʊ)ˈmatɪk/Chiefly Mineralogy
adjective
Changeable in colour; many-coloured; (of a mineral) deriving its colour or optical properties from a minor impurity that is not an essential part of its composition.
Origin
Mid 19th century; earliest use found in James Nicol (1810–1879), geologist. From allo- + chromatic, after German allochromatisch.