Learn about these strange glass blobs that showered the Earth millions of years ago.
Tektites are pebble-sized, often intricately shaped glass objects. They are much like obsidian glass, which is formed by terrestrial volcanic eruptions, except tektites have a far higher melting point and a thousand times less water content. Tektites are mainly composed of silica and contain bands of lechatelierite silica glass, which is formed naturally when lightning strikes quartz sand. Under the microscope, they display very little or no crystal structure.
This theory is supported by the fact that strewn fields of tektites surrounding one impact area are distinct from the type of tektites found surrounding another impact site.