Mineral surfaces - Part II: Structure and reactivity
Humanity has a long history of curiosity about the solids of the Earth and applying them as objects of beauty, wealth, power and practical advantage. From the first use of a stone tool, through the bronze age, iron age, the time of the alchemists, the ageof coal, steam and steel and now the silicon age, we have exploited minerals and shaped them to our purposes. For a couple of centuries, analytical tools have allowed us to identify mine-rals and describe their physical and chemical properties, so their bulkcomposition and structure are reasonably well characterised. Likewise, methods have been available for defining the compositionofsolutions and gases. Interactions between solids and fluids have been explored and conceptual models have been proposed for how atoms come to and leave surfaces, but only recently have we been able to confirm or disprove these models through direct observation at the molecular scale. It is the reactions that take place at the interface between phases that determine the properties of them both. An understanding of the mechanisms responsible offers scientists a powerful tool in pre-dicting the behaviour of the natural world and in engineering materials that continue to suit our purposes.
Whether Earth scientists are interested in the crystallisation of a melt in a magma chamber, or the recrystallisation that results in a diagenetic cement in a sandstone, or the accumulation of precious elements to form an ore deposit, or a hydrocarbon reservoir, or in the wide dispersal of contaminants throughout environmental systems, or the uptake or release of gases by a soil ora subduction zone, the chemical processes are the same.