Tektites were formed from terrestrial material that splashed back from an asteroid impact. The broken theory that tektites were of lunar origin was refuted years ago. There are many tektite "strew fields" that originated from different asteroid impacts. The most common (and cheapest) tektites come from the Philippines and China (same strew field). The nicest tektites (nice aerodynamic shapes) come from the Australian strew field. I collect tektites and have both types. We get whacked by a big asteroid about every10-20 million years which is why there are all these strew fields.

The commoness of tektites provides a good argument for colonizing Mars.

Gary