This special issue of the European Journal of Mineralogy honours the memory and life’s work of Werner Schreyer (1930–2006; see Seifert & Maresch, 2007, American Mineralogist, 92, 708–710), who through his own prolific studies and considerable energy and enthusiasm aroused the interest of petrologists and mineralogists in chemical systems that are both amenable to laboratory study and applicable to nature. Werner’s undergraduate and graduate education was in geology and petrology at the Universities of Erlangen and Munich. He received his doctorate at Munich (1957), and then held a post-doctoral appointment at the Geophysical Laboratory (1958–1962) before obtaining his Habilitation at the University of Kiel (1962–1966). He was appointed Full Professor of Mineralogy and Petrology at the newly founded Ruhr University in Bochum in the year 1966. Even after retiring in 1996, he remained highly active in science up until just before his death. He authored or co-authored over 250 publications, largely in international journals. A recipient of many scientific honours and awards, including a mineral named after him (schreyerite – V2Ti3O9), he said that to him the greatest honour was the Roebling Medal, awarded by the Mineralogical Society of America in 2002. Having been trained as a geologist, Werner never lost sight of the need to make laboratory studies pertinent to interpreting minerals and rocks in the field. He had a genius for teasing out surprisingly large amounts of information from but a handful of samples, or even a single one, and then often combined his field studies with precisely planned laboratory experiments to open new avenues of research.

To pay tribute to Werner’s approach, Walter Maresch, Edward Grew and Friedrich Seifert organized a special session at the 17th V.M. Goldschmidt Conference in Cologne on August 21 and 23, 2007 (see Elements, 2007, vol. 3, p. 376). The session featured 11 oral and 10 poster presentations (abstracts were published in Geochimica et Cosmochimica Acta, vol. 71, issue 15, supplement 1) by contributors from Australia, Austria, Belgium, China, England, France, Japan, Russia and the United States of America. Topics of the presentations encompassed Werner’s own intellectual breadth, but with a focus on his core interests in the mineral cordierite, phase petrology in the MgO–Al2O3–SiO2–H2O (“MASH”) system with particular emphasis on mineral assemblages equivalent compositionally to cordierite, high- and ultrahigh-pressure minerals and assemblages, as well as borosilicate phases in the model system “MABSH”. Werner and his colleagues were among the first to synthesize several compounds known only as minerals, and vice versa: Werner synthesized compounds that he suspected could form in nature and indeed natural analogues were subsequently discovered.

The papers in this comprehensive issue are written largely by contributors to the special session at the V.M. Goldschmidt Conference in Cologne, but certainly by no means limited to them. Indeed, the spontaneous response to the call for papers, together with the selfless, prompt and in-depth work of the many reviewers who have made this collection a resounding success, can be taken as a lasting and fitting tribute of many friends and colleagues to Werner Schreyer. The papers are grouped and ordered according to Werner’s core interests.