Part of a series, "Geology of Construction Materials" aims to show the connections between academic geology and the needs of the extractive industry by recognising that there is a direct relationship between the processes of mineral formation in the Earth's crust and the mode of occurrence and essential properties of the mineral. This book is intended to be useful to undergraduates in geology and related disciplines and the young graduate working in the extractive industry, although it is not intended as a working handbook. The book draws its information from many scientific, technical and trade journals and includes many examples from the United Kingdom. The differences between these examples and those in western Europe, northern America and developing countries are noted.