Gusaba:Imashini ya Vertical ring gradient wet magnetic itandukanya imashini yakoreshejwe cyane mugutandukanya ibishashara kubutare bwicyuma cya magnetique nka hematite, limonite, siderite, chromite, limonite, wolfram nibindi kimwe no gutandukanya ibyuma kugirango bisukure amabuye y'agaciro atari ubutare, nka quartz , feldspar, ijoro, fluorite, kaolin nibindi