The important manganese steels of commerce and certain nickel steels are manganiferous and niccoliferous austenite, unmagnetic and hard but ductile.
If, on the other hand, the carbon-content is to be raised, then carbon and manganese are usually added together in the form of a manganiferous molten pig iron, called spiegeleisen, i.e.
Of much more importance are the manganiferous and the silver manganiferous ores, which are much the richest of the country.
Their product trebled from 1889 to 1903; and in 1907 the output of manganiferous ores amounted to 99,711 tons, valued at $251,207.
Sometimes they are surrounded by halleflinta and limestone, as at Dannemora, Langban, Pajsberg, and then carry manganiferous minerals.