An Article In Meteorite-Times Magazine
by Paul Harris
Below is an Australite tektite from the Australasian Strewn Field. During formation, a spinning blob of tektite glass had an angular rotation high enough to cause it to stretch out, getting thinner in the middle, causing it's dumbbell shape. The dumbbell left the atmosphere either completely cooled or it finished cooling to a rigid body before it's re-entry into Earth's atmosphere? The below specimen became aerodynamically stable upon it's re-entry.
The Anterior side of this dumbbell became strongly heated during it's re-entry causing it to become a thermally shocked area which burst completely away. No flanged material remains on this specimen.
An interesting observation is that the "Dividing Ring" is a straight line. This indicates that the specimen was a cold rigid body when it re-entered the Earth's atmosphere. If not the specimen would have most likely bent in the middle due to the forces acting upon larger surface area of both ends of the dumbbell.
Recommended Tektite Books:
McCall, G.J.H., 2001, Tektites in the Geological Record, The Geological Society London
Heinen, Guy, 1998, Tektites – Witnesses Of Cosmic Catastrophes, Guy Heinen