Made-made glass is first recorded in Egypt some 5500 years before present, with hollow glass production from 3500 years before present. Glass blowing commenced around 2000 years ago. At one time it was suggested that Moldavites were in fact man-made glasses. Other, less attractive man-made glass is formed as the by-product of smelting metals such as iron and is known as 'slag'.
Understanding how glasses of different chemical compositions behave when they are cooled and heated is key to tektite studies. Input from professional glassmakers/experts would probably go a long way to understanding sculpture on tektites. Hal Povenmire also points out the problem of Stokes's Law, which deals with the way bubbles rise in a liquid, in relation to tektite formation. The argument is that pure tektite glass could not form, as bubble free as it is, in such a short time as invoked by the impact hypothesis. To counter this I would suggest that the huge velocities of ejection and centrifugal forces need to be taken into account.
ABOVE: A variety of glasses from the Victoria and Albert Museum in London.
ABOVE: Antique 'Onion' Bottles in the Victoria and Albert Museum in London. Kind of similar to Onion tektites.
ABOVE: A bowl that was partially melted in the Hiroshima Atomic Explosion. This is located in the Science Museum in London. Meteorite impacts are similar in many ways to atomic blasts, where a large amount of energy is released in a short time. When atomic blasts melt the ground an impactite-like melt rock called 'Trinitite' is formed.
Below is a piece of desert sand. This sand was melted by a gas flare during a drilling operation, i.e. it was melted in situ. Interestingly the bubbles and layering does not resemble Moung Nong tektites, which I do not believe were formed in situ.
ABOVE: Two pieces of glass formed by the melting of desert dune sand by a controlled gas flare in the Middle East. Note the absence of any flow structure.