Calculations of amphibole chemical parameters and implementation of the 2004 recommendations of the IMA classification and nomenclature of amphiboles

Abstract

The amphibole group is a complex, compositionally diverse group among silicates, and exists in large varieties of rock types and P -T ranges making it very useful P -T and petrogenetic indicator. In 2004 the International Mineralogical Association (IMA) revised its 1997 nomenclature scheme for amphiboles to accommodate all known amphibole species including several species discovered after 1997. The main difference between the 1997 and 2004 schemes is that amphiboles were divided into five groups in the 2004 scheme instead of four groups in the 1997 scheme. ClassAmp is an MS Excel -VBA program that implements the 2004 IMA revisions of and additions to the 1997 nomenclature scheme of amphiboles. In addition to implementing the new nomenclature scheme of amphiboles, ClassAmp is flexible where it can be used to classify microprobe or wet chemical analysis; obtain any combination of amphibole's cation names, cation values, structural formula names, structural formula values, groups, names, prefixes, and modifiers; properly format chemical symbols, associated with amphibole nomenclature so that the output can be directly imported to final drafts/publications; and determine pressure -temperature involves amphiboles as well as other petrogenetic determinations.