A companion volume to the "Atlas of rock-forming minerals in thin section", this full-colour handbook is designed to be used as a laboratory manual both by elementary students of earth sciences undertaking a study of igneous rocks in thin section under the microscope, and by more advanced students and teachers as a reference work. The book is divided into two parts - Part one is devoted to photographs of many of the common textures found in igneous rocks with brief descriptions accompanying each photograph. Part two illustrates the appearance of examples of some sixty of the commonest (and a few not so common) igneous rock types; each photograph is accompanied by a brief description of the field of view shown. Nearly 300 full-colour photographs are included, and in many cases the same view is shown both in plen-polarized light and under crossed polars. A brief account of how thin sections can be prepared is included as an appendix.

Photographs and brief descriptions of various types of rocks, minerals, and microtextures.

At a time when 'textural' evidence is regarded as being 'obvious' ( . . . ) it becomes more and more difficult to find illustrations or even descriptions of the arrangements of the various constituents of 'traumatized' rocks. It is helpful in consequence to advise geology students that the study of thin sections is not only concerned with the identification of their mineral content. To do so would mean they could not see the wood for the trees. Accurate identification of the indi vidual minerals that form rocks is fundamental in their description but the analysis of their textures and habits is also essential. Study of textural features enforces constraints upon the inter pretation of the origin and history of a rock. The analysis of micro textures cannot and should never be an aim in itself, out must be sup ported by qualitative and quantitative correlations with theories of petrogenesis. The aim here is to help the reader to bridge the gap between his observations of rocks unqer the microscope and petrogenetic theories. The habits or architectures of crystals in rocks may resemble those studied by metallurgists and glass scientists. Analysis of micro textures is undergoing change engendered by comparisonS between manu factured and hence minerals. This can be seen from the increased number of publications dealing with crystal ~rowth or deformation processes at microscopic scales to which the name of 'nanotectonics' has been applied.

This concise volume is designed for the introductory undergraduate level. With the help of colour photographs, the authors explain how to observe, describe and identify thin section samples of rocks and minerals using the polarizing microscope.