Siderite

Part of speech: noun (n.)

1. 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.

2. A meteorite consisting solely of metallic iron.

3. An indigo-blue variety of quartz.

4. Formerly, magnetic iron ore, or loadstone.

5. Any plant of the genus Sideritis; ironwort.