Abstract:For investigation of the crystal chemistry, oxygenation and facies changes of calcium amphibole, two specimens from Guangdong ands Beijing (named G- and B-specimen, respectively) were studied with Mossbauer spectroscopy. Each specimen was divided into five groups, four of them were heat treated under 600,800℃,1000℃,1200℃,respectively, and left one untreated. The results of Mossbauer measurements indicated that the occupancy ratio of Fe2+ and Fe3+ and oxygenation of Fe2+ change slowly with temperature below 600ºC,the oxygenation of Fe2+ increases-sharply between 600t to 801Jt,and the temper- atures of perfect oxygenation of Fe2+ to Fe3+ for these specimens are near 1000℃.During 1000℃ to 1200℃,the facies changes take place in the speci- mens. The new facies are magnetite and pyroxene mineral etc. For calcium amphiboles formed in different . geological occurrence, the ranges of perfect oxygenation temperature are somewhat different. For the B-specimen formed in lower temperature, perfect oxygenation and facies change take place at <1000℃,for G-specimen, at >1000℃. These results are coincident with X- ray powder diffraction analyses.