Too Thick to be a Meteorite Fusion Crust

Fusion crusts are thin because as soon as the exterior of the meteorite melts, the liquid is sloughed off due to of the high velocity of travel of the meteoroid through the atmosphere. The fusion crust does not build up, except perhaps on the trailing side. Meteorite fusion crusts are rarely greater than 1-2 mm thick.

Most of the crusts in these photos result from spheroidal weathering.