Habte, A. T., S. D. Mekonnen, A. N. Alene, and G. Y. Abate. “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, Vol. 7, no. 1, Oct. 2020, pp. 1-8, doi:10.9734/ajacr/2020/v7i130171.