[G., f. spiegel mirror + eisen iron.] A crystalline and lustrous variety of white manganiferous cast-iron much used in the Bessemer process for the manufacture of steel.
1868. Joynson, Metals, 53. A much higher … quality of iron is required to make steel by the Bessemer process, and, generally, a quantity of Spiegeleisen is required to be added to it.
1890. W. J. Gordon, Foundry, 102. Spiegeleisen is pig-iron’s most highly carburized and crystalline form.
So Spiegel iron.
1883. G. P. Lathrop, in Harper’s Mag., Aug., 334/1. A rill of snapping, scintillating spiegel-iron is let in.
1884. Knight, Dict. Mech., Suppl. 839/2. We have a spiegel iron in this country; it is made from the New Jersey Franklinite ore, and was at first called Franklinite iron.
