One of the mysteries that scholars have puzzled over for centuries is the exact shade of blue represented by “tekhelet,” which the Bible mentions as the color of ceremonial robes donned by high priests and ritual prayer tassels worn by the common Israelite.
What [is] known about tekhelet (pronounced t-CHELL-et) is that the Talmud said it was produced from the secretion of the sea snail, which is still found on Israeli beaches. Traditional interpretations have characterized tekhelet as a pure blue, symbolic of the heavens so that Jews would remember G-d. Not so, according to an Israeli scholar who has a new analysis: tekhelet appears to have been closer to a bluish purple.
The scholar, Zvi C. Koren, a professor specializing in the analytical chemistry of ancient colorants, says he has identified the first known physical sample of tekhelet in a tiny, 2,000-year-old patch of dyed fabric recovered from Masada, King Herod’s Judean Desert fortress, later the site of a mass suicide by Jewish zealots after a long standoff against the Romans. “It really is majestic,” Dr. Koren said of the shade, which he said remained close to its original hue and appeared to be indigo.…
The fabric he examined was one of many items discovered at Masada in the 1960s and stored at Hebrew University in Jerusalem. It came to his attention when a British historian, Hero Granger-Taylor, who specializes in ancient weaves, asked him to analyze some textiles. Dr. Koren said he was the first researcher to make the connection between the fabric and the snail dye. He found that the dye used in the Masada sample, a piece of bluish-purple yarn embroidery, came from a breed of Murex trunculus snail familiar to modern Israelis. Such shades on textiles are rare finds since they were typically worn exclusively by royalty or nobility.
Determining what exactly tekhelet would have looked like in its day has been the subject of conjecture and curiosity among rabbis, religious commentators and scientists for centuries; it is considered the most important of the three ritual colors cited in the Bible. The other two are argaman, a reddish purple, and shani, known as scarlet. “It’s especially exciting for religious Jews who place great importance on this color,” said Daniella E. Bar-Yosef Mayer, a University of Haifa archaeologist specializing in mollusk shells.
Some time after the Jews were exiled from Israel in A.D. 70, the knowledge of how to produce the tekhelet dye was lost. The dye was also prohibitively expensive to make: hundreds of snails were used to make even a small batch, and some in ancient times claimed it was worth 20 times its weight in gold.…
In modern Hebrew, “tekhelet” is the word for light blue.… The blue of the Israeli flag was inspired by tekhelet.… [However], even though [the new finding suggests that tekhelet] is not [sky blue], Dr. Koren said, the traditional notion of tekhelet—meant to serve as a reminder of the heavens—still fits. “Tekhelet is the color of the sky,” Dr. Koren said in his laboratory. “It’s not the color of the sky as we know it; it’s the color of sky at midnight.” He paused and added, “It’s when you are all alone at night that you reach out to G-d, and that is what tekhelet reminds you of.…”