Reviews in mineralogy and geochemistry. Epidotes / Эпидот

Our understanding of rock forming geological processes and thereby of geodynamic processes depends largely on a sound basis of knowledge of minerals. Due to the application of new analytical techniques, the number of newly discovered minerals increases steadily, and what used to be a simple mineral may have turned into a complex group. A continuous update is necessary, and the "Reviews in Mineralogy and Geochemistry" series excellently fulfills this requirement. The epidote minerals have not yet been covered and we felt that this gap should be filled.

The epidote mineral group consists of important rock-forming minerals such as clinozoisite and epidote, geochemical important accessory minerals such as allanite, and minerals typical for rare bulk compositions such as hancockite. Zoisite, the orthorhombic polymorph of clinozoisite, is included here because of its strong structural and paragenetic similarity to the epidote minerals. Epidote minerals occur in a wide variety of rocks, from near-surface conditions up to high- and ultrahigh-pressure metamorphic rocks and as liquidus phases in magmatic systems. They can be regarded as the low-temperature and highpressure equivalent of Ca-rich plagioclase, and thus are equally important as this feldspar for petrogenetic purposes. In addition, they belong to the most important Fe3+bearing minerals, and give important information about the oxygen fugacity and the oxidation state of a rock. Last but not least, they can incorporate geochemically relevant minor and trace elements such as Sr, Pb, REE, V, and Mn. <...>