Varlamoffite from Vernéřov near Aš (Czech Republic)
Abstract
The mineral varlamoffite was found in 1970 on a dump of an exploition shaft at Vernérov near As (Czech Republic). It occurred as a rare secondary mineral in quartz-amblygonite-microcline stockwork with sulfide-cassiterite mineralization. Varlamoffite of green-yellow colour forms compact aggregates up to 3 cm in size, containing relics of small grains of cassiterite exhibiting light brown to black-brown colour shades. Chemical composition, XRD and thermal data of varlamoffite are given. Varlamoffite of the Vernérov locality originated as a product of secondary alteration of cassiterite. In these authors' opinion, this mineral represents cryptocrystalline, hydrated variety of cassiterite with varying admixture of Fe203, Si02 and H20.