flgdecl1000004758_-00_isreal-flag-decalHey! It’s the flag of Irsael: a blue Star of David on a white background between two blue stripes.  What’s the story with all of that blue anyway?  Well, like most stories involving Judaism, the story goes back a long, long way to the Holy Temple of Jerusalem, where the high priests wore a robe dyed a deep midnight blue.  In fact, this color, known as tekhelet, was a sacred color which appeared in temple hangings and in the twined fringes known as tzitzit which hang from the corners of Jewish prayer shawls.

A High Priest with Tekhelet Robe

A High Priest with Tekhelet Robe

The Tanahk (the sacred books of Judaism) are pretty specific about tekhelet.  It is mentioned nearly 50 times and it is specifically and explicitly stated that the special blue dye must be made from a shellfish called chilazon (rather than from the less expensive indigo).   And so it was for many lives of men.  Unfortunately everything went wrong in the first and second centuries AD when the Roman Empire destroyed the temple, defeated a Jewish revolt and exiled Jews from Jerusalem.  During this period of chaos and diaspora, the fine nuances of dyes were not of tantamount importance, and the way to make tekhelet were lost as was knowledge of exactly what sort of mollusk a chilazon actually is.

Oh, also, during travel, the Ark of the Covenant was supposed to be covered in a cloth of tekhelet

Oh, also, during travel, the Ark of the Covenant was supposed to be covered in a cloth of tekhelet

The Talmud demands that tekhelet be used for crafting the fringes of prayer shawls and it stipulates that counterfeit dyes must not be (knowingly) used.  This has left devout Jews with a conundrum as to how to proceed.  Since the Roman exile, Orthodox Jews have most commonly setteld plain white tzitzit, however there have also been several attempts to rediscover the mysterious chilazon and recreate tekhelet.   In the late nineteenth century the Grand Rabbi Gershon Henoch Leiner researched the subject and proclaimed that the common cuttlefish, Sepia officinalis, was the missing mollusk.  The dye he created, however, did not seem to fit Talmudic descriptions and chemists later determined it was simply Prussian blue (although the holy man proudly wore his blue fringes, as did many of his followers).

Common cuttlefish - Sepia officinalis (photo by David Nicholson)

Common cuttlefish – Sepia officinalis (photo by David Nicholson)

Hexaplex trunculus

Hexaplex trunculus

Another Talmudic scholar cross referenced his ancient religious text with modern malacology texts and concluded that the chilazon was actually Hexaplex trunculus, a murex snail which is a close relative of  Murex brandaris (the source of Tyrian purple).   The dye which he created from the secretions of Hexaplex trunculus was also purple and thus did not seem to fit the bill.  Only with the help of a chemist in the 1980s was it determined that the proper blue color could be obtained by exposing a solution of the snail slime dye to sunlight.  So if you are an orthodox Jew (or a high priest of the Temple) you might want to look into getting some tekhelet clothing.

Actual Tekhelet dyed wool (probably...)

Actual Tekhelet dyed wool (probably…)