Meteorites & Tektites

ODESSA METEORITES The Odessa meteorite is iron-nickel Group I, coarse octahedrites. The Odessa crater, near Odessa, Texas was discovered in 1920. The crater and the meteorites found in it were first described in 1922 by Daniel Barringer.

The Odessa crater is approximately 500 feet in diameter, about 6 feet deep, with its rim rising about 6 feet above the surrounding plain. The crater is filled with about 30 feet of sand. Drilling attempts to locate any large, surviving meteorite(s) in the main crater, along with 4 surrounding smaller craters did not prove successful. This has lead some to believe that the main body of the meteorite probably vaporized on impact.

SIKHOTE-ALIN METEORITE SHRAPNEL The Sikhote-Alin meteorite fell in the Maritime Territory, Federated SSR, USSR on February 12, 1947. The total known weight was over 25 short tons (23,000 kg). The fall of this iron meteorite produced 106 impact holes up to 92 feet in diameter over an area of 328 ft x 2165 ft in the thick forest of the Sikhote-Alin Mountains. Many fragments weighing up to 660 pounds in weight have been recovered.

When a very large meteorite hits the earth it can explode into thousands of smaller pieces. This happened with some of the largest masses of the Sikhote-Alin fall. These pieces of torn and twisted nickel-iron metal were ripped apart by tremendous force when the comic body hit the Earth. They are called shrapnel fragments because they look very much like the twisted metal of a bomb explosion. However, they still preserve characteristics of their meteorite nature in the way they have cracked and torn.

HENBURY METEORITES The Henbury meteorite fall was discovered in 1931. The largest of the Henbury meteorite craters is about 590 feet wide and 49 feet deep. It is located about 87 miles south of Alice Springs in Central Australia. The craters were formed by several meteor impacts around 4700 years ago. Twelve craters have been identified, some not more than 20 feet wide and an inch deep. These iron meteorites are composed primarily of various alloys of iron and nickel. Structural class is medium Octahedrites (IIIAB)

TEKTITES are small pieces of silica-rich (usually 65-80% SiO2) glass found in limited areas in a few regions on the Earth's surface. They are similar in composition and appearance to volcanic glass such as obsidian with colors generally ranging from black to green. Formed under somewhat mysterious conditions that preclude a volcanic (terrestrial) origin, F.E. Suess (who introduced the name tektite in 1900) considered them to be glassy meteorites. However, unlike other meteorite types, tektites have not been seen to fall from the sky.

There are two current theories as to the origin of tektites. Both agree that the production of the molten silicate needed to form a tektite is the result of the impact of comets or large meteorites. Tektites are formed when a comet or meteorite collides with the earth - or moon - with such force that melted rock is "splattered" into the upper atmosphere. Here the droplets cool and harden into the shiny glassy shapes we call tektites.

The specimens offered below are Indochinite Tektites which are 70-80% SiO2. Indochinite tektites are the best known of the tektites coming from the Paulin District of Thailand. They are the classic teardrop and cigar shapes found in rice paddies throughout southeast Asia in Thailand, Laos and Vietnam. Tektites are generally found in strewn fields that are sometimes thousands of miles across.

MOLDAVITE TEKTITES We also have some Czechoslovakian Tektites which are the result of a meteor strike nearly 15 million years ago. This collision between a meteor and the Earth occurred in the Moldau River Valley in what is now the Czech Republic. These green gems are among the rarest minerals on earth. The color varies from a gray green to an emerald green. They can be carved with diamond cutting tools into various shapes and forms. Moldavites are claimed to have mystical qualities.