“薰衣草”紫晶的宝石学特征研究

Study on Gemological Characteristics of "lavender" Amethyst

“薰衣草”紫晶呈淡紫色,内部不通透,呈现丝绒质感,是近年来水晶市场出现的新品种。本文采用常规宝石学检测,红外光谱、激光拉曼光谱、紫外可见光谱测试以及激光照射对“薰衣草”紫晶的宝石学特征做了系统的研究。红外光谱、激光拉曼光谱以及紫外可见光谱均显示“薰衣草”紫晶主体为单晶石英。此外,对样品的拉曼图谱基线校正后,发现“薰衣草”紫晶拉曼特征峰普遍向低波数偏移2.3~3.3 cm-1,表明其内部微小包体的存在使石英晶格产生了内应力。样品经激光照射时出现丁达尔效应,认为其呈现的丝绒感是由内部包裹体对光散射造成的,且包裹体为非物质型或与水晶本体成分相同的纳米级包裹体。

Lavender amethyst is light purple, with impermeable interior and velvet texture. It is a new variety in the crystal market in recent years. In this paper, the gemological characteristics of lavender amethyst were systematically studied by conventional gemological detection, infrared spectroscopy, laser Raman spectroscopy, ultraviolet visible spectroscopy and laser irradiation. Infrared spectrum, laser Raman spectrum and ultraviolet visible spectrum all show that the main body of lavender amethyst is single crystal quartz. In addition, after the baseline correction of the Raman spectrum of the sample, it was found that the Raman characteristic peak of "lavender" amethyst generally shifted 2.3~3.3 cm-1to the low wave number, indicating that the existence of its internal micro inclusions caused internal stress in the quartz lattice. The Tindall effect appears when the sample is irradiated by laser. It is believed that the velvet sensation is caused by the scattering of light by the internal inclusions, and the inclusions are immaterial or nano scale inclusions with the same composition as the crystal body.