GOETHITE, a mineral crystallizing in the orthorhombic sys tem and isomorphous with diaspore and manganite (q.v.). It con sists of an iron hydroxide, first noticed in 1789, and named after the poet Goethe. Crystals are prismatic, acicular or scaly in habit ; they have a perfect cleavage in one direction. Reniform and stalactitic masses with a radiated fibrous structure also occur. The colour varies from yellowish or reddish to black ish-brown, and by transmitted light it is often blood-red; the streak is brownish-yellow; hardness, 5; specific gravity, 4.3. The best crystals are the brilliant, blackish-brown prisms with terminal pyramidal planes from the Restormel iron mines at Lostwithiel, and the Botallack mine at St. Just, Cornwall. A variety occurring as thin red scales at Siegen, Westphalia, is known as Rubinglimmer or pyrrhosiderite; lepidocrocite is a scaly-fibrous variety from the same locality.