A corroded, axe-shaped lump of iron unearthed from a ritual site in southwest China was forged entirely from a meteorite, according to a recent study published in Archaeological Research in Asia.
The artifact was found buried upright at Sanxingdui, a Bronze Age site in the Sichuan Province already famous for its bronze masks, figurines, and ceremonial trees.
To date, a total of 13 meteoritic iron artifacts have been identified in China, with most found in the country’s north.
Researchers have dated the artifact to the late Shang Dynasty (roughly 1600–1046 BCE), confirming it to be the largest artifact made from meteoritic iron ever found in the area.
Additionally, the study noted that while most artifacts found in northern China were found embedded within bronze weapons and buried with important individuals, the one discovered in Sanxingdui seems to have been made entirely from meteoritic iron.
What the object was actually used for remains unclear. Despite the context surrounding its discovery, which suggests ritual significance, the study explained that bronze artifacts found at the site bear cut marks made from extremely hard tools.
According to researchers, this raises the possibility that the artifact was in fact a working tool rather than a ceremonial one.
Identifying artifact’s meteorite origin
The key to identifying the artifact’s origin lay in its chemical makeup, the study noted, adding that an initial field analysis using a handheld X-ray scanner showed that the artifact was made up of more than 90% iron and 7.41% nickel.
Such a combination is rarely found in naturally occurring iron ore, but is characteristic of iron found in meteorites.
A follow-up laboratory analysis using electron microscopy in order to reveal a more in-depth chemical composition, confirmed that the artifact contained nickel levels of roughly 20%, which are far higher than the median of around 11% seen in other Chinese meteoritic iron finds.
Additionally, the iron's internal structure showed no signs of the intensive hammering or other techniques that would indicate human metalworking. This, combined with the near-impossibility of producing the iron-nickel alloy using ancient smelting techniques, further ruled out the possibility of the artifact being man-made.