Iron, IAB-MG
TKW 30 metric tons. Fall not observed. Impacted about 50,000 years ago. Found 1891 in Coconino County, Arizona, USA, between Flagstaff and Winslow.
Shun-Chung writes:
This is a carbon nodule weathered off from Canyon Diablo iron. Most of CD carbon nodules are composed of graphite - they can be split by kitchen choppers. However, this one is literally a devil! The carbon has been transformed to diamond (specifically, lonsdaleite) by the extremely high pressure and temperature when the iron hit the earth. It was almost uncuttable and ungrindable.
Craig Zlimen bought the whole nodule, and tried to halve and grind it. It instantly flattened diamond wheels, tore teeth off bandsaw blades, and bent diamond sintered blades. Finally, after months of scratching diamond on diamond he conquered this badass!
Fig. 1 and 2 a half piece in Shun-Chung Yang’s collection
Fig. 3 zoom in on the cut face
Fig. 4 the whole piece before cutting
Fig. 5 conversation between Craig Zlimen and Marlin Cilz
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