Hundreds of snails were necessary to dye cloths, making tekhelet prohibitively expensive.
Scholars are still debating whether tekhelet was a sky-blue color or a rather a darker, purple-hued blue. Traditional interpretations indicate that tekhelet was a sky blue, symbolic of the heavens.
The newly identified fragment is sky blue.
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Tests on the structure of the fabrics revealed the two purple fragments were most likely imported, while the tekhelet cloth was produced in the same fashion as the local fabrics.
"This sky blue fabric from the Dead Sea regions is definitive proof of both a colored fabrics trade and strict adherence to the biblical commandment of tekhelet in ancient Israel," Sukenik said.
How the precious fabrics got into the caves remains a mystery.
According to te IAA researchers, they may have belonged to Jewish refugees from the time of the Bar Kochba Revolt (132-136 AD) against the Roman Empire.
Another theory is that the clothing may have belonged to a Roman military unit stationing by the caves after the Bar Kokhba revolt.