Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce and increasingly expensive. We are republishing these classic works in affordable, high quality, modern editions, using the original text and artwork.

The rapid growth of gemological sciences and mineralogy demands a dictionary such as this for gemologists, mineralogists, geologists, jewel dealers, industry and hobbyists. With some 16,000 comprehensive definitions, supplemented by more than 250 diagrams and figures, this is a one-stop reference to any matter dealing with gems and gemology.

Understanding gemstones in a geological context Gemstones are colorful treasures of the Earth that have captivated humans for thousands of years. The physical and chemical characteristics of each type of gem provide insights into the geological processes that created them. Geology and Mineralogy of Gemstones is a textbook aimed at upper-level undergraduate and graduate students. It presents the basic mineralogical and geological knowledge needed to understand gemstones and examines the characteristics and geological origins of different types of gemstone. Volume highlights include: Concepts in mineralogy Structure and chemical composition of minerals Geological processes that lead to the formation and movement of gemstones Equipment and tools used to examine gemstones and their physical properties The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

A knowledge of clay is important in many spheres of scientific endeav our, particularly in natural sciences such as geology, mineralogy and soil science, but also in more applied areas like environmental and mater ials science. Over the last two decades research into clay mineralogy has been strongly influenced by the development and application of a num ber of spectroscopic techniques which are now able to yield information about clay materials at a level of detail that previously would have seemed inconceivable. This information relates not only to the precise characterization of the individual clay components themselves, but also to the ways in which these components interact with a whole range of absorbate molecules. At present, however, the fruits of this research are to be found principally in a somewhat widely dispersed form in the scientific journals, and it was thus considered to be an appropriate time to bring together a compilation of these spectroscopic techniques in a way which would make them more accessible to the non-specialist. This is the primary aim of this book. The authors of the various chapters first describe the principles and instrumentation of the individual spectro scopic techniques, assuming a minimum of prior knowledge, and then go on to show how these methods have been usefully applied to clay mineralogy in its broadest context.

A concise, systematic, yet comprehensive ``textbook'' treatment of the science. Examines origin, chemistry, crystallography, physical properties, and optical properties of gemstones, and discusses methods and instruments used to determine these properties. Highlights recent advances and important contributions; explores new methods of study and determination, crystal structures, causes of color, new gem minerals, new methods of gem synthesis, manufactured gems, chemical compounds used as substitutes, and imitations and simulations. Includes 12 full color plates, 350 halftones and line drawings, and a Gem Index that lists commonly sought characteristics along with page number references.