LEACHING AND RECONSTRUCTION AT THE SURFACES OF DISSOLVING CHAIN-SILICATE MINERALS

Abstract

THE pathways by which silicate minerals transform to solutes, clays and amorphous solids are relevant to a wide range of natural, industrial and even medical concerns. For example, weathered layers on silicate may have a high sorptive capacity, affecting nutrient and contamination retention in soils; less obviously, such layers on inhaled silicate grains might affect their interaction with lung tissue. Here we report the observation, in dissolution experiments on a range of chain-silicate minerals, of the formation of a near-surface amorphous region enriched in silicon and hydrogen, and depleted in other metals. Raman spectroscopy and ion-beam elemental analysis show that portions of the pol..