(Zak Rosen)

In the Book of Numbers, it is written that God said to Moses: “Speak to the sons of Israel, and tell them that they shall make for themselves tassels on the corners of their garments throughout their generations, and that they shall put on the tassel of each corner a cord of blue.” Yet it is comparatively rare to see Jews wearing prayer shawls with blue thread added to the fringes. Why this intransigence?

The short answer is that it’s an extraordinarily difficult commandment to fulfill, and one over which people have puzzled for centuries. Religious Jews believe that the blue used on tzitzit must be the same blue as was used in ancient times, and the source of that blue, referred to in the Bible as tekhelet, has been shrouded in mystery for over a thousand years.

Now, thanks to the efforts of a motley crew of rabbis, chemists, marine biologists, and archaeologists from around the world, it appears the mystery has been solved. Vox Tablet sent reporter Zak Rosen to the Mediterranean coast of Israel to meet tekhelet expert Baruch Sterman, author of The Rarest Blue: The Remarkable Story of an Ancient Color Lost to History and Rediscovered, to find out why this discovery took so long. [Running time: 17:31.]

Diving for Tekhelet
Photographs by Zak Rosen