SPIEGELEISEN
spiegeleisen, spiegel, spiegel iron
(noun) pig iron containing manganese; used as a deoxidizing agent and to raise the manganese content in making steel
Source: WordNet® 3.1
Etymology
Noun
spiegeleisen (countable and uncountable, plural spiegeleisens)
A ferromanganese alloy containing approximately 15% manganese and small quantities of carbon and silicon.
Historically, spiegeleisen was the standard form in which manganese was traded and used in steelmaking.
Source: Wiktionary
Spie"gel*ei`sen, n. Etym: [G. spiegel mirror + eisen iron.]
Definition: See Spiegel iron.
Source: Webster’s Unabridged Dictionary 1913 Edition