gems, spinel, Burma, Mogok, Man Sin, Tanzania

In recent years, spinel has attracted increasing attention for its unique charm, especially the hot pink spinels from Man Sin, Myanmar and Tanzania, which have been enthusiastically received by the market amidst a surge in demand for spinel. However, despite their popularity, gemmological and spectroscopic studies on these hot pink spinels remain limited. To better understand their gemmological and spectral characteristics, modern analytical techniques such as X-ray fluorescence spectrometry (EDXRF), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet–visible–near infrared (UV-Vis-NIR) spectroscopy were employed. Comparative analysis was conducted on samples from Man Sin and Tanzania. The results show that MgAl₂O₄ is the main terminal component in the Man Sin spinel samples, which also contain trace elements such as Cr, V, Fe, Zn, and Ca. The Ca content in Man Sin samples ranges from 0.017% to 0.034%, whereas the Ca content in the Tanzanian samples is approximately 56 times higher on average. In the UV-Vis-NIR spectra, Cr³⁺ is responsible for a strong absorption peak at 686 nm, V³⁺ causes an absorption peak at 435 nm, and Fe²⁺ contributes to peaks at 370 nm and 585 nm. These main chromogenic elements provide a scientific basis for distinguishing geographic origin, owing to the significant differences in Cr, V, Fe, and Ca contents between localities.