The unique bright bluish-green color of turquoise as a high-grade jade has long receivedwide attention.The relationship between the color of turquoise and its composition and struc-ture is described in this paper on the basis of chemical data,EPR,magnetic susceptibility,ab-sorption and Mssbauer spectra.The results show that the basic color of turquoise(brightblue)is related to the existence of octahedrally on the amount of iron.EPR,magnetic susce-blue through green to earth-yellow is dependentcoordinated Cu~(2+) and the shade variation fromptibiIity,and crystal-field spectra of Cu~(2+) have been analyzed and compared with the theoreticalcalculations.A preliminary discussion is also made of the color change as a function of tempera-ture. The unique bright bluish-green color of turquoise as a high-grade jade has long received wide attention. The relationship between the color of turquoise and its composition and strucure is described in this paper on the basis of chemical data, EPR, magnetic susceptibility , ab-sorption and Mssbauer spectra.The results show that the basic color of turquoise (brightblue) is related to the existence of octahedrally on the amount of iron. EPR, magnetic susce-blue through green to earth-yellow is dependentordinated Cu ~ ( 2+) and the shade variation fromptibiity, and crystal-field spectra of Cu ~ (2+) have been analyzed and compared with the theoreticalcalculations. A preliminary discussion is also made of the color change as a function of temperaure.