Some examples of extraterrestrial rocks are tektites, meteorites and lunar basalt. It is also often used for the area containing tektites produced by large meteorite impact. Indochinites are distinctly dark black in contrast to the green of European moldavite tektites. Vitreous silicon dioxide is known as tektites, and obsidian, and rarely as lechatelierite. It also contains small globules of glassy material called tektites, formed in the initial impact. The difference in water content can be used to distinguish tektites from terrestrial volcanic glasses. The hypothesized Pantasma Impact Crater in northern Nicaragua might be the source of these tektites. He wrote widely on numerous subjects, including tektites, meteors and the steady-state universe theory. The ages of tektites from the four strewnfields have been determined using radiometric dating methods. Small particles resembling green glass, and later identified as tektites, were found at the site. Their age corresponds with the age of other tektites in the Australian strewn tektite field. The terrestrial source for tektites is supported by well-documented evidence. This theory was a development of O'Keefe's unusual hypothesis on the origin of tektites. Australites are smaller than other tektites and different in shape. Millimeter-scale tektites are known as microtektites.