Sid"er*ite, n. [L. sideritis loadstone, Gr. &?;&?;&?;&?;, &?;&?;&?;&?;,
of iron, from &?;&?;&?;&?; iron.] 1. (Min.) (a) Carbonate of iron, an
important ore of iron occuring generally in cleavable masses, but also
in rhombohedral crystals. It is of a light yellowish brown color.
Called also sparry iron, spathic iron. (b) A meteorite consisting
solely of metallic iron. (c) An indigo-blue variety of quartz. (d)
Formerly, magnetic iron ore, or loadstone.