Definition:  Corrosion products are materials which are derived from the destruction of another material by a chemical reaction with the environment it is in. Every year corrosion results in massive costs to industry.  Accurate analysis and identification of corrosion products is one of the first steps in determining the causes of corrosion.  To give you an idea of the variety of these materials some of the phases we have encountered in corrosion products include, goethite, magnetite, maghemite, lepidocrocite, akaganeite, greigite, mackinawite, pyrrhotite, wuestite, tenorite, cuprite, pyroaurite, green rust, feroxyhyte, hazlewoodite, atacamite, paratacamite, botallackite, triolite, cinnabar, galena, and laurionite, and certainly this list is not exhaustive.

Analysis: X-ray powder diffraction is a very useful technique capable of the identification of a very wide variety of corrosion products.  Samples can be analysed in powder form but it is also possible with some samples to analyse surface deposits without removing them from the object.  Most corrosion deposits are multiphase but despite their complexity we have developed methods that can give semi-quantitative estimates of phase abundance.  We can also work with very small samples (milligrams) if necessary, though we prefer to work with a few grams if available.