Spiegeleisen
Spiegeleisen (
German:
Spiegel—
mirror;
Eisen—
iron) is a ferromanganese
alloy containing approximately 15%
manganese and small quantities of
carbon and
silicon. Historically, this was the standard form in which manganese was traded and used in
steel making (see
Bessemer process); today, manganese is usually traded and used in more concentrated form, 80% manganese content being typical.