What is the difference between a meteorite and a tektite?
A meteorite is a piece of a space rock. A tektite is natural glass made from Earth rock melted and flung out by a large meteorite impact.
Meteorites and tektites are both connected to impacts, but they are fundamentally different.
Meteorites come from space. They are pieces of asteroids, the Moon or Mars that survived the fall through Earth's atmosphere. They are made of minerals such as olivine, pyroxene and iron-nickel metal, and usually have a fusion crust formed during their fall.
Tektites are made of Earth rock. When a large asteroid or comet hits Earth, the impact can melt surface rocks and throw droplets of melt high into or above the atmosphere. These droplets cool into glass and fall back, sometimes hundreds or thousands of kilometres from the crater. Tektites are usually black, dark brown or green, glassy, and may have aerodynamic shapes such as spheres, teardrops, dumbbells or buttons.
Known tektite strewn fields include: - Moldavites, green tektites in central Europe from the Ries impact in Germany, about 14.8 million years ago. - Australasian tektites, including indochinites and australites, about 788,000 years old, scattered across a tenth of Earth's surface. - Ivory Coast tektites, from the Bosumtwi crater in Ghana, about 1.1 million years old. - North American tektites, linked to the Chesapeake Bay impact, about 35 million years ago.
How to tell them apart. Tektites are glass with no crystals, are not magnetic and are lighter than most meteorites, with densities about 2.3 to 2.5 grams per cubic centimetre. Meteorites usually contain metal, are often magnetic and are denser.
Tektites are collected and valued, but they are not meteorites.