An anonymous collector holds the largest portion, which weighs 925lb. in 2008, this piece was expected to fetch $2million (£1.26million) at auction at Bonham’s in New York – but it remained unsold.
It is so valuable that even tiny chunks sell in the region of £20-30 per gram.
Arizona’s Southwest Meteorite Laboratory, which holds about 70lb of the rock, says the remarkable find will turn out to be ‘one of the greatest meteorite discoveries of the 21st century’.
It says the Fukang specimen outshines all other known examples of the pallasite class, which makes up just one per cent of all meteorites.
However, it is not the biggest – in 2005 space rock hunter Steve Arnold dug up a 1,400lb sample in Kansas.
The Arizona lab’s experts say pallasites, whose make-up of half nickel-iron, half olivine gives them their mosaic-like appearance, are ‘thought to be relics of forming planets’.
They are believed to originate from deep inside intact meteors created during the formation of the solar system about 4.5 billion years ago and very few specimens are thought to have survived their descent through Earth’s atmosphere.