molysite
/ˈmɒlɪsʌɪt/Mineralogy
noun
Ferric chloride as a trigonal mineral, occurring as yellow to brownish or purplish red deliquescent encrustations in areas of volcanic activity, especially near fumaroles.
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From Hellenistic Greek μόλυσις stain + -ite. Hellenistic Greek μόλυσις (also μόλυνσις; rare; compare more common Hellenistic Greek μολυσμός, Byzantine Greek μόλυσμα) is from ancient Greek μολύνειν to stain (probably a formation in -νυ- from an unattested adjective) + -σις.