Pyrite. A Natural History of Fool's Gold. By David Rickard. Oxford University Press, 2015. Hardback, XIX+297 pages, 4 colour plates. Price GBP 20.49. ISBN 9780190203672.

Almost three centuries have passed since Henckel’s monumental work on pyrite (Henckel, 1725, 1757). The new book by David Rickard, world authority on sulfide chemistry, geochemistry, geomicrobiology, biogeochemistry and ore geology, is a most welcome state-of-the-art report about this humble but fascinating mineral. As stated in the preface, the book targets a popular rather than an academic audience; the latter is referred to the impressive research monograph on sulfides published three years before (Rickard, 2012). Nevertheless, a wide-ranging basic education spanning from chemistry to physics, from geology to biology, is necessary to get the most from this comprehensive text in which the author has summarized an impressive amount of data and knowledge. The preface is followed by a prologue, which sets the landscape where pyrite will be hunted in all its aspects in the ten chapters which compose the book. Each chapter is complemented by a series of notes that go beyond the simple bibliography. The journey ends with an epilogue, followed by an extensive (17 pages) index. The book also includes the colour versions of 16 figures printed as four colour plates just before page 203. As clearly stated in the Prologue, this book aims at demonstrating a thesis: pyrite has accompanied and even shaped our civilization since its beginning, not only in the extractive metallurgy, to recover the various metal impurities, but also for its use as a source of sulfur for the black powder (army industry) and of sulfuric acid used in chemicals (e.g. fertilisers), the textile industry (vitriols used as mordants) and pharmaceuticals (alums). It has even contributed to the evolution of early life, as described by the iron–sulfur world model (Wächtershäuser, 1992); it keeps providing us with fundamental pieces of information about the history of the Earth and can be used to predict the future changes in the environment, noting that human activity has increased the rate of pyrite oxidation, making the environment more acidic. These may overall sound like overstatements, but the journey in the sulfidic ocean that the reader undertakes by opening this book should convince him of the primary role played by this mineral in the major events of our planet. The analysis is really a 360 approach, including an historical analysis of pyrite nickname ‘Foole’s Gold’ (the archaic spelling emphasizing the ancient root of this naming) that dates back to the false attribution of pyrite crystals as gold already at the time of the Sumerian civilization. More recently, this same confusion led to the first European settlement in the New World, which was established precisely in the quest for gold, which turned out to be pyrite. This historical approach is complemented by detailed philological analyses – which include the reasons why sulfur has changed to sulfur – of the Sumerian, Arabic, Akkadian, Persian, Greek and Chinese names. The origin of the name pyrite is traced back to the clay tablets produced by the Sumerians and emphasis is put on the long confusion with the term marcasite, often used in jewellery to indicate pyrite, but which indicates the polymorph (actually, polytype) metastable at ambient conditions. We learn that up to Henckel (1725, 1757) the presence of iron escaped to most investigators, even Agricola mentioning an ore of sulfur and ‘stone’. The alchemical description is taken only in its literal meaning, and thus obviously severely criticized, ignoring its role of secret language under which ancestral esoteric practices were hidden to escape the Catholic repression (Evola, 1931, 1999). ISSN 2052-5206