The samples studied are collected from the Quarternary residual drift bed. The chromian pyrope has been supposed to be derived mainly from the nearby porphyritic chromian pyrope-chrome diopside-enstatite-peridotite. The present stone has been well known on its bright red color, purity arid transparency. The faceted gem reveals its excellent quality which may be com- parable with the best know n"Bohemian Ruby". The present pyrope is rather peculiar in color. When the quality of illu- urination is altered, the color of the mineral changes to such an extent that an alexandrite-like effect is seen.In transmitted daylight the pyrope appears red- dish violet, in lamplight it is ruby-like red. The wave length of optical absorption spectra of Cr ions for the present pyrope is 5500一5600 A,4000一4100 A. With its absorption spectra of Cr ions less than the critical value of 5800A and 4150A,the present pyrope appears red in color. The color indices of the transmition color of chromium-containing pyrope are Tais 25 .36 x 0.3649 y 0.3252 λd-495nm Pe0.09.
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王福泉,1984,江苏某含铬镁铝榴石的宝石矿物学研究[J].岩石矿物学杂志,3(1):33~39.,1984,Study on Gemological Mineralogy of Chromium-Containing Pyropes of Jiangsu Province[J]. Acta Petrologica et Mineralogica,3(1):33~39.