A newly studied artefact from south-west China is drawing renewed attention from archaeologists after laboratory tests revealed a composition unlike typical Bronze Age materials.
Excavations at the Sanxingdui site in Guanghan are prompting some new questions about how ancient societies obtained and worked with unusual metals. Sanxingdui, long associated with the Shang dynasty, has produced numerous discoveries to date, including large bronze masks, figures, and other ritual items.
A small bracelet-like piece, measuring around 20 centimetres, was found in one of the site’s sacrificial pits. Its composition is very remarkable, with an unusually high nickel content (around 7%) according to an analysis.
This combination is unusual for metal objects from the Bronze Age, when metalworking primarily relied on copper and its alloys, such as bronze. Iron was not widely used at the time, and certainly not in combination with nickel at this level.
To understand the material in detail, scientists conducted X-ray imaging and electron microscopy. The nickel was evenly distributed throughout the object. Such uniformity is difficult to achieve even with state-of-the-art techniques, raising questions about the content of the material itself.
According to a study published in Archaeological Research in Asia, such consistency would have been extremely difficult to achieve using known methods from the late Shang period.
One explanation under consideration is that the raw material did not originate on Earth in the usual way. Iron with a high nickel content is commonly associated with meteorites.
Supporting this idea, researchers also identified structural features—specifically grain patterns—that form under very slow cooling conditions. These conditions are typical of space environments rather than those found on Earth’s surface.
If this interpretation is correct, it suggests that ancient craftspeople may have worked directly with meteoritic iron rather than producing the metal themselves. Instead of smelting ore, they may have shaped a naturally occurring fragment that had fallen to Earth.
While this is unusual, it is not entirely without precedent. Small objects made from meteoritic iron have been discovered in other parts of the world, although such finds remain rare.
The Sanxingdui artefact is also notable for its size and composition. Researchers believe it is the largest known example of meteoritic iron use in China to date.
Unlike many other items from the site, which are often decorative or symbolic, this piece is plain and undecorated. Its hardness suggests it may have served a practical function, possibly as a tool used in working bronze or other materials.
The artefact is currently in a fragile condition due to corrosion built up over thousands of years. It is being kept under controlled conditions to prevent further deterioration. Scientists hope to identify the exact type of meteorite from which the material originated, although further testing may be limited to preserve the object.
Sources : Archaeological Research in Asia
