Some of these forms will show a slight ridge on occasion indicating ablation, but the Australites are the real aerodynamic shaped tektites. In their case ablation has done much to give them their form. Australite buttons have a hemispherical side often showing a spiraling raised line. The technical name for this is "ring wave'' it is a featured created as the surface melted, partly burned away, and partly re-deposited in the flange. The flange of Australite buttons is a ring of material around the original core that builds up but does not completely weld itself to the original mass. On occasion the entire forward facing side and flange will detach leaving a distinctive core. These flangless cores are found also. Australites come in elongated forms as well as round.
It is however clear in some cases that they are found in essentially the spot they fell and in a specific layer or horizon in the ground.
by The Meteorite Exchange, Inc : http://www.meteorite.com/