iron blue

American  

noun

1. any of the class of blue pigments having a high tinting strength and ranging in shade and in coloring properties from reddish blue to jet blue: used chiefly in the manufacture of paints and printing inks.

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Etymology

Origin of iron blue

First recorded in 1690–1700

Example Sentences

Make the iron "blue hot," and it pours out, in addition to light, the invisible waves which alter the film on the photographic plate.

From The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told by Thomson, J. Arthur

Vitriol, vit′ri-ol, n. the popular name of sulphuric acid: a soluble sulphate of a metal—green vitriol=sulphate of iron, blue vitriol=sulphate of copper, white vitriol=sulphate of zinc.—v.t.

From Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) by Various