n. n. 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.n. A meteorite consisting solely of metallic iron.n. An indigo-blue variety of quartz.n. Formerly, magnetic iron ore, or loadstone.n. Any plant of the genus Sideritis; ironwort.