Abstract In this work, the x-ray induced luminescence technique was used to investigate natural and imitation rubies. The red and pink natural rubies in the present work were provided from Myanmar and Vietnam, respectively. The imitation rubies (red and pink glasses) in glass were taken from imitation jewelry company in Thailand. Optical, compositional and structural were studies to confirm the identification of natural and imitation stone. X-ray diffraction (XRD) study reveals that natural rubies contain α-Al2O3 as the major phase. On the other hand, XRD does not show sharp peak for imitation ruby stone, therefore it indicates that the imitation rubies are made of amorphous material (glass). Absorption spectra in visible region of natural rubies, red and pink glasses show a prominent absorption band around 520–560 nm wavelength with Cr3+ transitions, gold nanoparticles and Er3+ transitions, respectively. Photoluminescence (PL) emission spectra of both natural rubies show strong red emission at 692 nm (λex = 577 nm), relating to Cr3+ transition (2Eg→4A2g). The green emission peak at 548 nm (λex = 403 nm) of imitation ruby (pink glass) was observed; it comes from the transition of Er3+ (4S3/2 → 4I15/2). The x-ray induced luminescence (XIL) spectra of natural rubies show similar pattern with PL result, while XIL of imitation rubies cannot be observed. This XIL result show the fast separation behavior between natural and imitation rubies. Therefore, XIL is suitable for using as a luminescence analysis of gemstones because of their fast process, non-destructiveness and without excitation wavelength special sample-preparation needs.

中文翻译：

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天然和仿制红宝石的 X 射线诱导发光、光学、成分和结构研究：鉴定技术

摘要 在这项工作中，X 射线诱导发光技术被用于研究天然和仿制红宝石。本作品中的红色和粉色天然红宝石分别来自缅甸和越南。玻璃中的仿红宝石（红色和粉红色眼镜）取自泰国的仿珠宝公司。光学、成分和结构研究以确认天然和仿制石材的识别。X 射线衍射 (XRD) 研究表明，天然红宝石含有 α-Al2O3 作为主要相。另一方面，XRD 没有显示出仿红宝石的尖峰，因此表明仿红宝石是由无定形材料（玻璃）制成的。天然红宝石可见光区的吸收光谱，红色和粉红色玻璃在 520-560 nm 波长附近显示出明显的吸收带，分别具有 Cr3+ 跃迁、金纳米粒子和 Er3+ 跃迁。两种天然红宝石的光致发光 (PL) 发射光谱在 692 nm (λex = 577 nm) 处均显示出强烈的红色发射，这与 Cr3+ 跃迁 (2Eg→4A2g) 有关。观察到仿红宝石（粉红色玻璃）在548 nm（λex = 403 nm）处的绿色发射峰；它来自 Er3+ (4S3/2 → 4I15/2) 的转变。天然红宝石的 X 射线诱导发光 (XIL) 光谱显示出与 PL 结果相似的模式，而无法观察到仿红宝石的 XIL。此 XIL 结果显示了天然和仿制红宝石之间的快速分离行为。因此，XIL 适合用作宝石的发光分析，因为它们的处理速度快，