Stibnite (Sb2S3), the principal natural source of Sb in the environment, is linked to the parent weathering material of sinarmonitis (cubic Sb2 O 3 ), stibiconite (Sb 3 O 6 OH), and valentinitis (orthorhombic Sb 2 O 3) ( Hu, Guo, He, & Li, 2016 ). It has been calculated that volcanic activity is responsible for 3%–5% of worldwide Sb emissions ...