Surface morphology of iron dendrites in the Yanzhuang H6 meteorite

In the Yanzhuang H6 meteorite are small (10μm to 7mm) Fe-Ni dendrites in pockets and veins. We have characterized the surface morphology of several of the dendrites by using scanning electron microscopy (with X-ray microanalysis). The dendrite surface has a network of growth ledges. At the edge of the apexes of the dendrites, there are four concentric “rings” which are consistent with a 〈111〉 dendrite growth direction to produce four ring patterns parallel to the “100” planes. The Fe dendrites are partially coated with a material containing growth ledges which is rich in Fe and S, and is presumed to be FeS (troilite).