In this research, a comparative study of the natural amethysts from Thailand and Myanmar. The physical, structural and compositional properties were studied. The results indicate that the density of natural amethyst is between 2.632±0.0083-2.638±0.0050 g/cm³. The XRD diffraction patterns result can be confirmed the crystalline nature of both natural amethysts. The chemical composition analysis shows that the amethysts are mainly composed of silicon dioxide, sodium oxide and aluminium oxide, respectively. From comparing the source for amethysts, it was found that the Fe₂O₃ content in amethyst from Thailand is the highest value, which enhances the depth of purple color compared with amethyst from Myanmar.