Meteorites are fragments of objects in the solar system other than earth, most of which come from asteroids between Mars and Jupiter, and a few from the moon and Mars. More than 40,000 meteorite samples have been collected all over the world. They can be roughly divided into three groups: stone meteorites (mainly composed of silicates), iron meteorites (iron-nickel alloys), and stone iron meteorites (a mixture of iron and silicate).
It's the type of meteorites that fall the most. The general term for meteorites composed mainly or entirely of silicate minerals, especially magnesium iron silicate, in which the metal iron-nickel content is less than 30%. According to the existence of chondrules or not, the rock structure can be divided into two categories: chondrites and achondrites. According to the overall chemical composition, chondrites can be divided into carbonaceous chondrites, common chondrites and choriosite chondrites. The tertiary classification of achondrites is also based on chemical (mineral) composition. Rocks with high calcium content are called calcium-rich achondrites, while rocks with low calcium content are called calcium-poor achondrites. Stone meteorites are similar in composition and appearance to ultrabasic rocks with a density of 3~3.5 g/cm '. It is easily mistaken for a normal rock in the wild, so although it has a large number of falls, accounting for more than 92 percent of the total, the number of meteorites found accounts for only 56.3 percent of the total.
The vast universe, the vastness, there are too many unknown waiting for mankind to explore. Meteorites known as "exotic rocks" have long been loved by astronomers and geologists for their high scientific value. Today, meteorite collections are sweeping the world, and the ability to collect meteorites has become a status symbol for collectors. Stone iron meteorite also known as meteorite. Meteorites are relatively rare, accounting for 2% to 4% of meteorites. The content of iron, nickel and silicate minerals is equal (30%~65%). The main minerals are olivine, pyroxene, iron and nickel. Among them stone iron meteorite because of its unique historical value and scientific research value by the collection of the new rich chase.
down to earth every year more than 20 tons, meteorites number has more than twenty thousand, more than 99% of them are aerolite and iron meteorites, pallasite only accounts for almost 0.3% of proportion, in other words, a year down to the earth's pallasite only about $60, among them are part of the fall in the sea, and part cannot be discovered, and part of the collection in a large museum. Because of this, the commercial value and scientific value of stone iron meteorite is very high, even large collectors, can collect stone iron meteorite is also very few.