The Mazama ash includes plagioclase, hypersthene, magnetite, hornblende, clinopyroxene, and volcanic glass. It can be distinguished from other volcanic ash deposits, such as those from eruptions of Glacier Peak, Mount St. Helens and Mount Rainier, by the unique chemistry of those constituents. This can be determined by electron microprobe analysis, by the refractive index of the volcanic glass, and by neutron activation analysis and similar techniques. Radiocarbon dating of associated carbon-bearing material may also aid identification of the Mazama Ash.