The History of Biblical Blue

Why Biblical Blue (Techelet) ?

God commands the People of Israel:

"Hashem spoke to Moshe saying: Speak to the Children of Israel and say to them that they shall make themselves tzitzit on the corners of their garments throughout their generations. And they shall place upon the tzitzit of each corner a thread of Techelet... And you shall see it and remember all of the commandments of Hashem and you shall do them," Numbers 15:37-39

We are required to place a thread of blue on our tzitzit as a constant and conspicuous reminder of our stature as noble sons of the King of the Universe, always pursuing His mitzvot (commandments). What is the significance of this unique blue color known as Techelet?

"And the Rabbis said: Why does the Torah enjoin us regarding Techelet? Because Techelet resembles sapphire, and the Tablets were of sapphire, to tell you that so long as the people of Yisrael gaze upon this Techelet they are reminded of that which is inscribed on the Tablets and they fulfill it, and so it is written, 'And you shall see it and remember.' Mishnat Rabbi Eliezer, ch. 14

In ancient times purple and blue dyes derived from snails were so rare and sought after that they were literally worth their weight in gold. These precious dyes colored the robes of the kings and princes of Media, Babylon, Egypt, Greece and Rome. To wear them was to be identified with royalty.

Techelet is Lost to the world

"And now we have only white, for the Techelet has been hidden." The Midrash, Numbers 17:5

The Mediterranean coast was the center of the dyeing industry in the ancient world. "Tyrian Purple" came from the port of Tyre in Phoenicia (now southern Lebanon). The Phoenicians made their wealth trading in the dyestuff, and dye houses were ubiquitous in the region. Because of its lucrative nature, purple and blue dyeing slowly came under imperial control.

The Romans issued edicts that only royalty could wear garments colored with these dyes, and only imperial dye houses were permitted to manufacture it. This apparently drove the Jewish Techelet industry underground. Later, with the Arab conquest of Eretz Yisrael (683 CE), the secret of Techelet was essentially lost, the dyeing process forgotten.

The Source: Chilazon Snail

"Rabbi Meir said: Whoever observes the mitzva of tzitzit, is considered as if he greeted the Divine Presence, for Techelet resembles the sea, and the sea resembles the sky, and the sky resembles God's holy throne."Sifre, Shelach, 15:39

The Biblical commandment to wear tzitzit is still observed today, but the prominent blue thread has all but been forgotten. What has remained are passages in the Talmud describing the source of the blue dye - a snail known as the Chilazon.

This marine creature had a shell, could be found along the northern coast of Israel, and its body was "similar to the sea." The dye's color was "similar to the sky and sea," it was steadfast, extracted from the snail while still alive, and was indistinguishable from a dye of vegetable origin, called kala ilan (indigo).

Searching for the Biblical Blue

"There is an obligation, upon all who are capable, to search for it [the Chilazon], in order to bring merit upon Israel with this commandment, which has been forgotten for the last several centuries. And he who succeeds in this will surely be blessed by the God of Israel." Rabbi Gershon Henoch Leiner

In 1858 the French zoologist Henri de Lacaze-Duthiers found that three Mediterranean mollusks produced purple-blue dyes. One, Murex trunculus, was determined by him (and other scientists, archeologists and historians) to be the source of the ancient Biblical blue.

In the same century, unaware of Lacaze-Duthier's findings, Rabbi Gershon Henoch Leiner: known as "the Radzyner Rebbe", set out on an expedition to search for the lost Chilazon in a grand effort to restore Techelet to the Jewish people. He was convinced that a certain squid fit the descriptions of the Chilazon.

However, unable to produce a blue dye from the black ink released from this squid, he turned to an Italian chemist, who provided him with a method. Within two years, ten thousand of the Rabbi's followers were wearing blue threads on their tzitzit.

Rabbi Leiner published two books to counter the strong opposition from other Torah scholars who did not agree with his conclusions.

Porphyrology: The Study of Purple

"The [squid] blood ... is mixed with iron filings and a snow white chemical called potash. After keeping it on a large powerful fire for some four or five hours, until the flames burn outside and inside as the fires of Gehenna, the mixture fuses..." from a letter sent by the Radzyner dye master to Rabbi Herzog

In 1913 the Chief Rabbi of Ireland, Rabbi Isaac Herzog (later Chief Rabbi of Israel), wrote a doctoral dissertation on the subject of Hebrew Porphyrology (the study of purple - a word he coined). When he sent samples of the Radzyn Techelet to chemists and dye experts for analysis, the dye was found to be inorganic - a synthetically manufactured color known as Prussian Blue. Refusing to believe that Rabbi Gershon Henoch had purposely misled his constituents, Rabbi Herzog studied the Radzyner dyeing process.

The truth soon became apparent. The process called for subjecting the squid ink to intense heat and then adding colorless iron filings to the mixture.

This produced the blue color which indeed appeared to come from the squid ink. In fact, under these conditions, virtually all organic substances would yield the same blue dye - the squid was not an essential component. The Rabbi had apparently been misled by an unscrupulous chemist.

Solving the Mystery

The vein is removed... and to this salt has to be added... three days is the proper time for it to be steeped, and it should be heated in a leaden pot with 50 lbs. of dye to every six gallons of water. Pliny the Elder, Natural History 9.61.133, first century BCE

Rabbi Herzog knew of the work done by Lacaze-Duthiers and others, and realized that all the evidence pointed to Murex trunculus as the most likely candidate for the Techelet source. Two problems, however, prevented Rabbi Herzog from positively identifying that snail with the Chilazon. First, the dye obtained from the trunculus was purplish-blue, not pure blue as tradition maintained. Second, this snail has an off-white shell with stripes of brown, hardly fitting the Talmudic description of the Chilazon as appearing similar to the sea.

Current research has supplied the solutions to these objections. The shell appears off-white with brown stripes when it is out of the water, cleaned and polished. In its natural element, however, trunculus is covered with a coat of sea fouling the color of the ocean. Everything in its vicinity is covered with the same fouling, making it almost impossible to distinguish the snail from the sea bed on which it is found. The Talmud's description is of the Chilazon in its natural habitat!

The riddle of producing a pure blue color from the snail was serendipitously solved. While researching the methods used by the ancient dyers, Prof. Otto Elsner, of the Shenkar College of Fibers, noticed that on cloudy days, trunculus dye tended towards purple, but on sunny days it was a brilliant blue! He found that at a certain stage of the dyeing process, exposure to sunlight will alter the dye, changing its color from purple to blue. To the dye masters of old, working in the bright Mediterranean sunlight, this was certainly no secret.

Murex Trunculus Snail: The Proof

"Have mercy on us and rebuild Your city speedily in our days, and bring us to peace, to our Holy Land, and let us merit the return and revelation of the Chilazon, that we may be privileged to fulfill the commandment of Techelet in tzitzit."from the prayers of Rabbi Nachman of Breslov

The evidence for identifying the Murex trunculus as the source of Techelet is decisive, and goes beyond merely fitting the general descriptions of the Chilazon as found in the Talmud:

The Jerusalem Talmud translates Techelet as porphiron (the Latin and Greek name for trunculus-like shells). Pliny and Aristotle describe these shells as the source of the ancient dyes.
The Talmud indicates that true Techelet is indistinguishable from the blue dye of vegetable origin - kala ilan (indigo). The dye ultimately derived from trunculus is molecularly equivalent to indigo.
Extensive marine biological surveys have revealed that the only snails in the Mediterranean which produce stable dyes are those of the Murex family. The dye obtained from trunculus is very stable and steadfast, which accords with the Rabbinical description of Techelet.
Archeologists in Tyre and elsewhere uncovered mounds of Murex shells dating from the Biblical period which were broken in the exact spot necessary to obtain the dyestuff. Chemical analysis of blue stains on vats from 1200 BCE reveals patterns consistent with those of modern day trunculus.
When listing the precious commodities used in building the Mishkan (tabernacle), the Torah consistently includes Techelet along with gold, silver, and other familiar materials, recognized by all for their worth. The Prophet Ezekiel speaks of the Techelet from Tyre and the "Isles of Elisha", and the Book of Esther informs us that in Persia, Mordechai wore royal clothes made of Techelet. Surely, the Torah is referring to that same valuable dye commonly used by royalty throughout the rest of the ancient world.