The role of crystal heterogeneity in alkali feldspar dissolution kinetics

Intrinsic heterogeneities of crystals almost always impose challenges on the investigation of dissolution kinetics. In the case of the incomplete solid solution series of alkali feldspars, additional complexity to the wide range in chemical composition and crystallographic characteristics is introduced in the form of chemical differentiation at low cooling temperatures. In this paper, we use direct measurements of intact crystal surfaces to quantify the dissolution rate of an alkali feldspar, providing details unavailable to powder dissolution experiments alone. In particular, we show how complex intergrowth textures characteristic of feldspars may play an important role in terms of how these minerals dissolve.