Abstract: Plagioclase is a continuous solid solution series of albite-anorthite, but its crystal structure is in continuous, which can be divided into several feldspar areas with different structure and attachment. Iridescent plagioclase in Peristerite area is albite-oligoclase; Iridescent plagioclase in B gild area is andesine-labradorite. Albite and labradorite both belong to plagioclase series, but they are the two different varieties. According to the characters of inclusion and transparency, iridescent labradorite is further divided into three varieties.