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I agree with Eric and Bob that many of the decisions of the International Mineralogical Association regarding mineral names are mistaken, unjust and lead to confusion. Take the nomenclature of the sodic amphiboles. It was first defined by Miyashiro (1957) and served well the needs of the petrological-mineralogical community until a new schema of nomenclature came out by an IMA committee in the late 1990's. The committee abolished the name of "crossite" redefined the compositional limits of the glaucophane, riebeckite etc. This was wrong on three accounts: 1. It created confusion. What is described as crossite before 1997 is now glaucophane, riebeckite, magnesioriebeckite or ferroglaucophane. 2. Miyoshiro's diagram had an underlying petrological sense. Blueschist metabasites generally contain crossite and glaucophane, whereas most eclogites contain glaucophane. This distinction is lost in the IMA nomenclature. 3. It is a disrespect for the memory of a great petrologist - the sodic amphibole diagram was known as the Miyashiro diagram. What is worse is that I cannot see a single good reason (except perhaps a love of symmetry?) as why the compositional limits of sodic amphiboles were redefined. These decisions were taken behind doors and very few of the interested people were consulted. A similar and probably worse case goes for the IMA sodic pyroxene nomenclature. I still use the established nomenclature for the sodic amphiboles and pyroxenes despite occasional objections by some editors. Aral Aral I. Okay Eurasia Institute of Earth Sciences and Department of Geology Istanbul Technical University [log in to unmask] http://atlas.cc.itu.edu.tr/~okay/index.html tel 90 212 285 6208 fax 90 212 285 6210