Iron Meteorites

Iron meteorites are composed largely of nickel-iron metal, and most contain only minor accessory minerals. These accessory minerals often occur in rounded nodules that consist of the iron-sulfide troilite or graphite, often surrounded by the iron-phosphide schreibersite and the iron-carbide cohenite. Despite the fact that some iron meteorites contain silicate inclusions, most have fundamentally the same superficial appearance.

Presently, iron meteorites are classified under two established systems. Just a few decades ago, iron meteorites were exclusively classified according to the macroscopic structures revealed when their polished surface was etched with nitric acid. Depending on these structures, they were separated into three classes: octahedrites, hexahedrites, and ataxites. 

IIIAB Group

With about 233 members, group IIIAB is the best-represented class of iron meteorites in our collections. Compared to the members of the IIIA subgroup, which have mostly coarse octahedrite textures, the IIIB irons usually display medium textures. Still, the members of both subgroups form a continuous sequence in structural and elemental compositions that suggests a common origin, probably representing different regions of an asteroid's core. Group IIIAB contains several prominent members representing some of the largest irons ever found. Just to name a few, there are the giants of Cape York, Chupaderos, Morito, and Willamette - have a look at our charts. Some IIIAB members contain large nodules of troilite and graphite, but silicate inclusions are rare. Despite this fact, recent research suggests a close relationship exists between the IIIAB irons and the silicate-rich main group pallasites, some of the most attractive stony-iron meteorites known. Both groups probably formed on the same parent body, a differentiated asteroid that was disrupted by a single impact event. The IIIAB iron meteorites represent fragments of the core, while the main-group pallasites are samples of the core/mantle boundary of this common parent body.

Henbury IIIAB     Year found: 1931 Country: Australia TKW : 2 MT
				Henbury-00 Complete oriented henbury, really pretty ! SOLD Price on request
Henbury-01 Complete slice showing nice structure ! 176 gr 875 $