Gemmological Characteristics of a Bright Green Glaucophane

A bright green pendant was examined in the lab of National Gold ＆ Diamond Testing Center of China(NGDTC).Although the colour of the pendant looks similar to jadeite or green nephrite，with the help of transmitted light，its colour is spotted but with no granular structure which is different from jadeite and green nephrite.In order to identify this mineral，NGDTC founds that its refractive index is 1.61～1.62and its colour under microscope with the bright field lighting presents as green water waves.Under the handhold spectroscope，two absorption lines were observed in the field of red light.NGDTC also founds that the reflective infrared spectrum of the specimen matches well with that of the amphibole in the jadeite.Referring to other studies and the spectra collected with KBr powder，the specimen was verified as glaucophane.The energy dispersion X－ray fluorescence(EDXRF)analysis also shows that the elements of the specimen are the same as those of the glaucophane tested by previous researchers.The characteristics of both the visible light spectrum and EDXRF analysis show that chroumium is the colouring element of this glaucophane specimen.