In the end of 2007, mysterious upward arcs at the ends of
the shear marks on four jade artifacts were discovered. Previously,
the marks were thought to be produced by stone cutting tools,
but those curved lines put this theory in doubt.
The jade blocks, each weighted tons and measured over a
meter long and about half a meter tall, were unearthed from
the world famous Three Star Mound (Sanxingdui 三星堆).
Ren Nan (任楠), a jade expert who is specialised in Red Hill
Culture (红山文化) research, believes that the marks must be
fashioned by highly precision instruments, such as slitting
The jade stones were among a large stash of relics discovered
by Sichuan peasant Yan Daocheng (燕道诚) in 1929 when his family
dredged a drainage in the field. Not realising their significance,
the family gave away the jades as presents or sold as building
materials, and left some of them by the road side. When one
day a Chinese archaeologist passed by, he noticed the shear
marks on the blocks and identified them as ancient artifacts.
But it is until more than half a century later in 1986, when
sacrificial pits containing thousands of gold, bronze, jade
and pottery artifacts were accidentally unearthed, that the
jade blocks started to be associated to a previous unknown
branch of ancient Chinese culture, which can be dated back
to the so-called Bronze Age.
When the jade artifacts were examined using infrared spectroscopy,
Chinese scientists found that mineral serpentine of the secondary
pollutant has transformed into tremolite, which requires
a long period to complete. Further tests by laser raman spectroscopy
confirms that the artifacts were made ten thousand years
(Source of news and photos: 中国收藏网)
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