Definition of siderotil in US English:

siderotil

noun

Mineralogy
  • A white to pale yellow or green mineral consisting of ferrous sulphate pentahydrate, often also containing copper and typically resulting from the oxidation of iron sulphides.

Origin

Late 19th century; earliest use found in Mineralogy Magazine. From German Siderotil from sidero- + Hellenistic Greek τίλος shred, fibre.