The Metbul provides the following basic information on Turpan 003. It is a IIIAB Iron found in the desert outside of Turpan City, Xinjiang Provenance China by Ashanjiang Mahemuti on 15 March 2022. Originally only a low gram count single find; additional searches over the course of the following year turned up multiple masses with a range of sizes from 20 grams to 32 kilograms. This brought the total know mass up to 80 kilograms. The Metbul further describes Turpan 003 as being composed of mm-scale iron-nickel blebs within a troilite matrix lacking Widmanstatten pattern.
Though there is no Widmanstatten pattern, Turpan 003 is far from pattern-less, having what could be easily argued as one of the more unique and discernible looks of meteorites that have come to market in the last few years. I would go as far as to venture its one-of-a-kind looks will bring it up-to-par with the famed Gujba, for being identified at-a-glance.
Though not used in the description of Turpan 003, dendritic is the terminology that describes the relatively unique structures. It’s a terminology not overly utilized in the Metbul, with only 42 returns for “dendritic” and 13 more for “dendrite”. Though the term pops up rarely in meteoritics, it’s occurrence spans the bulk of the classification spectrum being described in chondrites, achondrites and irons of various types.
The word dendritic derives from the Ancient Greek word déndron which means “tree”. It geological terms it describes crystal structures that have a branching structure away from a nucleation point (origin). The branching is a function of anisotropic growth in an environment subject to a rapid rate of cooling. The growth rate at the tip of the crystal structure is much higher than along its other faces. The rapid tip growth creates variances in the concentrations of ions available in the solution the crystals are forming out of. These variances in fluid composition then set up further anisotropic nucleation points along the flanks of the already grown crystal producing the classic looking smaller side branches.
