A catalog of analyzed calciferous and subcalciferous amphiboles together with their nomenclature and associated minerals

This paper presents 1217 analyses of amphibole having six percent or more CaO; physical constants are given for 1106, as well as half-unit cell contents of each, reference source, locality, mineral assemblage in which amphibole occurs, whether any coexisting mineral has been analyzed, indication of quality of analysis, and a name which conveys the composition of each amphibole. Ca 1.50 and above in the half-unit cell defines calciferous amphiboles, Ca 1.00-1.50 the subcalciferous. A rational nomenclature is proposed based on the well-known end members tremolite, richterite, tschermakite, edenite, pargasite, and hastingsite. Three important variables define the main name, and prefixes indicate unusual features. One-third of the analyses appear to be superior, one-third moderate, and one-third inferior; of recent analyses about half are superior. Frequency-distribution polygons show ranges of compositions and coexistence.