[meteorite-list] AD- Coins, Space Envelope and Stable Morasko !

[David Weir]

Hello,

According to Buchwald, the production of fusion crust does occur in 
irons, while heat-affected rim zones are present below this fusion 
crust. Partially quoting from his first volume, in the chapter Shapes 
and Surface Characteristics, he writes that these fusion crusts differ 
from those of stones in that iron fusion crusts consist of complex, 
mixed melts of fully and partially oxidized metal. The oxide melts have 
solidified and decomposed to wustite-magnetite layers, while the 
metallic melts have solidified to a multilayer dendritic-cellular zone 
transformed to fine-grained martensite. These fusion crusts are only 
sub-mm in depth, with another 10 mm of heat-affected zone, where the 
temperature didn't rise above 300-400*C. A nice diagram is shown on page 
52. I love the photos that are made of the fusion crusts after being 
coated with ammonium chloride.

David