ataxite

from The Century Dictionary.

• noun A meteoric iron, or siderite, which is destitute of distinct and regular crystalline structure.
• noun In petrography, a name proposed by Loewinson-Lessing, in 1888, for lavas characterized by the presence of many angular fragments, of irregular arrangement, the fragments being regarded as the result of the differentiation of the magma containing them and not as derived from any foreign source. See taxite.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A type of iron meteorite