Taupānga: Ka whakamahia nuitia te whakawehe autō rōnaki teitei i roto i te hematite mākū, limonite, siderite, chromite, ilmenite, wolframite, tantalum me te niobium ore me etahi atu kohuke aukume ngoikore, me nga kohuke kore-metallic, penei i te quartz, feldspar mo te tango i te rino poke me te purenga. .