Germanium is most often developed from sphalerite zinc ores but is usually recognized being extracted from fly ash coal (made from coal electrical power plants) and some copper ores.Nghiên c?u c?a FDA ??a ra k?t lu?n r?ng germani, khi s? ??ng nh? là ch?t b? sung dinh d??ng, "th? Hello?n m?t s? nguy Hello?m ti?m tàng cho s?c kh?e con ng??i".