Tektites are collected for their unique shapes and textures as natural oddities. They are glass. They are however, not glass like any other natural glass found on Earth. They form when asteroid hit the Earth and melt the rocks of our planet and send the liquid and vaporous rock material out to near space. There it cools and returns through the atmosphere. It receives during this process aerodynamic shapes apparently determined by the kind of spin the blobs of liquid glass had. Among the shapes are patty, sphere, rod, dumbbell, teardrop, and bubble forms. The bubble type nearly always breaking upon hitting the ground again. But, from the large number of bubble fragments we know there were many of this type.
Not all asteroid impacts create tektites. In fact there are only five area on our world where they can be found. This makes tektites a very desirable natural wonder to collect.
The tektite glass is very dry and gas free. Obsidian on the other hand as a volcanic glass is very abundant with water and gas in its composition. The extremely high temperatures of tektite formation account for this dryness and lack of gas.
Debate about tektites has gone on for a couple centuries. Today many of the questions about this fascinating objects have been answered. But, since no one has ever witnessed a tektite forming event some of the details of their creating remain points of debate.