Thermal ablation effects are the hallmark of Australites. Nearly all show them in some variation. Cores form as the incandescently-hot frontal surface expands and flakes explosively detach from the sides and front. In the following image, the flight direction was towards the top. All are classic Australite cores with well developed flake scars.
A few reported examples of thermally-ablated tektites outside of Australia are known, but not many. With the fingers of two hands, you can count them all. Java, Billiton, and the southern Philippines account for nearly all of them. No examples have been reported from China or mainland southeast Asia. There seems to be a northerly limit to their distribution which remains unexplained
Over the years we have sorted through a few million tektites, and we have a good eye for special stones. In our special pieces drawer are two (and only two) suspect thermal ablation cores from Thailand, possibly the first such specimens ever described.
The three in the center of this image are Australite cores. The two to the right are Rizalite cores. The two to the left of the scale cube are Thailandites, the star of this article. Are they for real?
The sideview image above is the most instructive view. Let the Australite profiles serve to calibrate your eye. The general nose-cone like form is not entirely coincidental. Australite morphology was studied in the designing process for early spacecraft nose-cones.
Thermal ablation can also take the form of melt formation and migration under stable oriented flight conditions, as with oriented meteorites. I believe the Thailandite specimens are frontal-fusion thermal ablation cores (if they are actually cores at all). For any who would ponder their significance, we have to consider their extreme rarity. For some reason this sort of nose-cone fusion almost never happened.
The less glamorous and more probable explanation is that these are deeply telescoped hersheys-kiss style tear drops that have almost fully re-engulfed their tails. An accidental coincidence of form. Another Tektite Teaser.