摘要
近期,燕山大学珠宝玉石鉴定研究中心收到了一些标称是"寿山石"的样品。采用常规的宝石学检测,测定了样品的折射率、密度、硬度等参数。结果表明,这种样品的折射率约为1.53,相对密度为2.31,摩氏硬度为2.5。虽然样品的颜色、硬度、折射率等与寿山石的都很接近,但是样品的密度低于寿山石的。为了确定其真伪,采用傅里叶变换红外光谱法和X射线粉末衍射法分别对样品进行了分析测试。测试结果表明,该样品主要由石膏和含水量不确定的烧石膏组成,并不含有地开石、珍珠陶石、叶蜡石、伊利石等组成寿山石的矿物相,是一种寿山石的仿制品。这种仿制品在外观上与寿山石很相似,常规宝石学参数也相似,但是前者的密度低于寿山石的。因此,建议检验机构在寿山石的常规检测中应该测定其密度,如果发现密度偏低,应采用其它手段进一步测试。
Some samples claimed as larderite were received at Yanshan University Gemstone Identification and Research Center recently. The refractive index, density and hardness of the samples were studied by using the conventional gemmological methods. The results show that the refractive index was 1. 53, the density was 2. 31 and the hardness was 2. 5. Although the samples were very similar to larderite in many aspects, such as in colour, refractive index, hardness and so on, its density was slightly lower. X-ray diffraction （XRD） and Fourier transform infrared spectrum （FTIR） were also used to identify the samples in order to decide whether they were larderite or not. The results of XRD and FTIR show that the samples were a kind of imitation since they were composed of gypsum and calcined gypsum with uncertain water content, and that the minerals such as dickite, nacrite, pyrophyllite and illite were not found in the samples. The imitation was very similar to larderite both in appearance and in parameters except that the density of the imitation was a little lower. The density of larderite should be tested in the routine check at the inspection stations. If the density of the stone is lower than the ordinary level, other methods should be used to make further identification.
出处
《宝石和宝石学杂志》
CAS
2012年第2期40-43,共4页
Journal of Gems & Gemmology
