The Reis Crater is the type locality for suevite and has been very well studied. It consists of a grey/brown matrix bearing angular clasts. The rock bears some surface resemblance to volcanic tuffs (rocks formed by the ash flows of volcanos), but differs in some important ways. The matrix consists of spindles of glass, remelted and shocked minerals, and small quanties of coesite and stishovite (quartz polymorphs which are only found at high pressure and temperatures). The rock formed under shock metamorphism and is not therefore volcanic in origin. However, studies of ignimbrite and pyroclastic flows may help with the understanding of suevite and its emplacement.
Weight, 36g. This photograph is of the item that is offered for sale.