Steve makes extensive use of X-ray powder diffraction in his work and his research interests revolve around a mixture of clay, soil and environmental mineralogy. Clay minerals are his specialty and he is a former Chairman of the Clay Minerals Group of the Mineralogical Society of Great Britain and Ireland. He set up and maintains the 'Images of Clay' archive a free to use for teaching purposes - clay mineral image gallery. Clay minerals are extremely varied and soil clay minerals are amongst the most difficult of all minerals to study and characterise. Many of the properties of soils are controlled by the clay minerals they contain, but understanding how mineralogy controls properties requires accurate techniques for clay mineral identification, characterisation and quantification. Steve's research is aimed at developing methods for clay mineral identification and quantification in soils and linking this to an understanding of soil properties and behaviour.The innovation of the XRPD quantitative methods developed by Steve is world renowned through his consistent success in the Reynolds Cup, and many of the same methods are offered as commercial services to industry via Ian Phillips, Helen Pendlowski and Nia Gray, all work together with Steve on various projects revolving around clay minerals.