红色长石的宝石学特征研究

近几年在国内外珠宝市场上出现了一种红色透明长石，其天然性引起了广泛的争议。采用常规的宝石学方法、LA—ICP—MS以及紫外-可见分光光度计等测试仪器研究了该红色长石样品的宝石学特征、化学成分及紫外-可见吸收光谱，旨在探讨其致色原因。结果表明，该红色长石样品属于中长石；与黄色长石样品相比，其化学成分中Cu的质量分数为739×10^-6～801×10^-6，远远高于黄色长石的（1．07×10^-6），而其它微量元素的质量分数则无明显的差别，故认为Cu可能与其呈红色有关；紫外-可见吸收光谱结果显示，该红色长石样品在可见光区的吸收带主要位于566nm处，推测其可能与Cu对可见光的吸收有关。

Study on Gemmological Characteristics of Red Feldspar

A type of red and transparent feldspar has recently appeared on domestic and overseas gem markets, whose natural characteristic is much controversial. For studying the origin of the red colour, the gemmological characteristics, chemical compositions and UV-VIS absorption spectra are tested by using the conventional methods, LA-ICP-MS and UV-VIS spectrophotometer. The results show that the red feldspar samples belong to andesine. Compared with the yellow feldspar samples, the content of Cu is 739×10^-6～801×10^-6 in the red feldspar samples, which is more higher than that in the yellow feldspar samples （1.07 X 10.6）, and the contents of the other elements have no significant differences. Therefore, the colour of the red feldspar samples may be related to the Cu. The results of the UV-VIS absorption spectra indicate that the red feldspar samples have the absorption band at 566 nm, which is due to intrinsic absorption of light caused by Cu.