mountain green
/ˌmaʊntɪn ˈɡriːn/noun
1 Mineralogy. Any of several green copper minerals, especially when used as a pigment; specifically (a) malachite; (b) chrysocolla; (c) glauconite.
2The dark green colour of various copper minerals or of mountain vegetations.
Origin
Early 18th century; earliest use found in Ephraim Chambers (?1680–1740), encyclopaedist. From mountain + green, after German Berggrün.