Electron microprobe analyses show the less contents of major chemical composition such as w(SiO2) 54.73% and w(BeO)(cal.) 45.62% in phenakite which are close to the theoretical values respectively. LA-ICP-MS indicates the contents of minor elements as well as the rare earth elements among which the contents of Ti and Fe are only 338×10-6 and 11.46×10-6, speculating brownish yellow color acquired by irradiation. The IR spectra exhibites the characteristic vibrations of phenakite which are assigned accordingly. The result shows two major vibrational bands center around 600~800 cm-1 and 850~1 100 cm-1. Phenakite can be readily distinguished with other similar gems by standard gemological testing and IR spectra.