Some few meteorites have "flow lines" but some terrestrial rocks, both natural and man-made, have flow features
Many people have told me that they think their rock is a meteorite because it has “flow lines.” Few meteorites have flow lines.
Flow lines and other flow-like features are common on meteorwrongs, however. The photos below were all sent to me by persons who inquired whether the object was a meteorite because it had “flow lines.” Note that none of the objects has a fusion crust. Note also that meteorite flow lines are external features – they only occur in the fusion crust on the outer 1-2 mm of the rock . It is clear in some of the photos that the lines are a reflection the internal crystalline structure of the rock, not a surface feature.
This is simple: If a rock does not have a fusion crust, then it does not, and cannot, have meteorite flow lines.