HABTE, A. T.; MEKONNEN, S. D.; ALENE, A. N.; ABATE, G. Y. FAAS, FT-IR and XRD Identification of Natural and Heat Treated Opals Located in Wadla Woreda, North Wello, Ethiopia. Asian Journal of Applied Chemistry Research, v. 7, n. 1, p. 1-8, 15 out. 2020.