From Middle Persian [Book Pahlavi needed] (gwklt'), 𐫃𐫇𐫃𐫏𐫡𐫅 (gwgyrd /⁠gōgird⁠/, “sulphur”), from Proto-Iranian *gawkr̥tah, from Proto-Indo-Iranian *gawkr̥tas. Cognate with Sogdian 𐫄𐫇𐫐𐫤 (ɣwkt /⁠γōkət⁠/), Kamkata-viri geřtë.