HONG KONG (Reuters) - Over 100 ancient jade artifacts in museums across southeast Asia have been traced back to Taiwan, shedding new light on sea trade patterns dating back 5,000 years, researchers said.
Using X-ray spectrometers, the international team of scientists analyzed 144 jade ornaments dating from 3,000 BC to 500 AD and found that at least 116 originated from Fengtian in eastern Taiwan.
"The chemical composition of jade reveals its origin and ... their analysis determined the relative amounts of iron, magnesium, and silicon in the jade," the scientists wrote in a paper published in the latest issue of the Proceedings of the National Academy of Sciences.
"Based on elemental composition, 116 artifacts were identified as originating in Fengtian. The source of the others remains unknown."
Fengtian jade has a distinctive translucent green hue and black spots.
The 144 artifacts were unearthed in archaeological excavations in Taiwan, the Philippines, Malaysia, Vietnam, and Thailand.
Odds and ends of Fengtian jade were found at several sites in the Philippines, Thailand and southern Vietnam, which the lead researcher Hung Hsiao-chun said may have been workshops.
"Fengtian jade was shipped to these workshops in southeast Asia, which dated from 500 BC to 100 AD. They were very small and they churned out these ornaments that were then exported to other places," said Hung, of the Australian National University in Canberra.
"What's really interesting is their products (from different countries) were very similar," she told Reuters in a telephone interview.
Jade earrings, beads, bracelets and pendants, some depicting two-headed animals, were popular in southeast Asia during the early Iron Age between 500 BC and 500 AD.
Prior to this period, however, Taiwan's jade ornaments were likely to have been crafted back home in Fengtian.
"There was a very huge workshop in Fengtian, dating back to 3,000 BC," Hung said, adding that one of the earliest pieces of Fengtian jade found in the Philippines dates back to 2,000 BC.
"Before, researchers thought all the jade in the Philippines was from China or Vietnam. With our analysis ... we found that most of the ornamental jade in the Philippines was from Taiwan."
The findings of Hung and her team revealed one of the largest prehistoric trades in semiprecious stone.
"Their seafaring methods must have been very superior, even back then," Hung said.
"What we know now is the origin of the jade. We need to find out who these craftsmen were and what tools they used. We know very little about their manufacturing process."
Editing by Rosalind Russell