The Sulphide Phase in Some Iron Meteorites

Abstract

METALLIC meteorites are composed in, varying proportions of two iron–nickel metallic solid solutions, kamacite, which has a low nickel content, and taenite, which has a higher nickel content. The structure and distribution of these phases have been extensively examined on a macro- and on a micro-scale. Many iron meteorites also contain non-metallic inclusions of an iron–nickel phosphide (schreibersite) or an iron–nickel sulphide (troilite). Troilite has not been subject to very detailed microscopic examination for two reasons. First, it shows a great tendency to chip and disintegrate during preparation and, secondly, it is very reactive towards most etching agents ; hence, when metallic meteorites are deeply etched for museum exhibition the troilite is usually protected from the etching agent by a suitable stopping-off compound.