For the little story
Tektites are fragments of terrestrial sedimentary rocks, torn from the ground during a meteorite impact under the effect of pressure and intense heat.
During the impact, the rocks melted by the shock are ejected at very high speed and can travel hundreds of kilometers.
During its ballistic trajectory, the viscous material will take its final shape and cool.
Note for example the spherical, ellipsoidal, dumbbell, drop, pear, teardrop, flat or bulging disc shape, etc.
The variety of shape of tektites comes from the various forces acting on them.
We will cite for example, cohesion forces (for the agglomeration of viscous material), centrifugal forces (during the rotation of the material) and aerodynamics (friction force and resistance to advancement).
The trajectory of a Tektite can be intra or extra atmospheric. This will obviously have consequences on its final form, entry into the atmosphere could cause cracks on the surface, sort of furrows like scratches.