Tekelet (Hebrew: תכלת, "turquoise" or "blue"; also techelet or techeiles) is a blue dye from a shellfish called Chilazon mentioned 50 times (or 48  ) in the Tanakh. It was used in the clothing of the High Priest, the tapestries in the Tabernacle, and the tassels (Hebrew: ציצית, tzitzit [tsiˈtsit], pl. tzitziot) affixed to the corners of one's four-cornered garments or to the four corners of one's tallit (prayer shawl) then and now.
After the destruction of the Temple in Jerusalem by the Romans, the sole use of the tekhelet (blue) dye was in tzitzit. A Tzitzit is made of four strands, which must be made with intent. These strands are then threaded and hang down, appearing to be eight. The four strands are passed through a hole 25 to 50 mm away from the corners of the four-cornered cloth. Judaism offers three opinions as to how many are to be blue: 2 strings; 1 string; 1 half string.
|“||37. The Lord spoke to Moses, saying: 38. Speak to the children of Israel and you shall say to them that they shall make for themselves fringes on the corners of their garments, throughout their generations, and they shall affix a thread of sky blue [wool] on the fringe of each corner. 39. This shall be fringes for you, and when you see it, you will remember all the commandments of the Lord to perform them, and you shall not wander after your hearts and after your eyes after which you are going astray. 40. So that you shall remember and perform all My commandments and you shall be holy to your God. 41. I am the Lord, your God, Who took you out of the land of Egypt to be your God; I am the Lord, your God.||”|
—Bamidbar - Parshas Shelach, Numbers 15:37–41
|Part of a series on|
|Jews and Judaism|
Biblical references 
Of the 50 (or 48 ) uses in the Masoretic Text, one refers to the whole nation of Israel (Numbers 15:37–41), 44 refer to the priesthood or temple. The remaining 6 in Esther, Jeremiah and Ezekiel are secular uses; such as when Mordechai puts on "blue and white" "royal clothing" in Esther. The colour could be used in combination with other colours such as 2 Chronicles 3:14 where the veil of Solomon's Temple is made of blue (tekhelet), purple (Hebrew argaman אַרְגָּמָן) and crimson (Hebrew karmiyl כַּרְמִיל). Various shellfish have been suggested for the source of the dye. Ezekiel 27:7 may indicate the source of the shellfish to have been the Aegean region.
Talmudic references 
The Talmud teaches that the source for the blue dye is a marine creature known as the khillazon (Hebrew: חילזון), translated as "snail" in Modern Hebrew. The Talmud also mentions a counterfeit dye from a plant called Kela-Ilan, known as Indigofera tinctoria, the ubiquitous source of blue dye in the ancient world. The Talmud explains that it is absolutely forbidden to use this counterfeit dye intentionally (i.e., if one was duped, the strings are still kosher, however they simply do not fulfill the religious requirement for tekhelet strings). The Tosefta explains that Kela Ilan is not the only invalid dye source. In fact, everything but the khillazon is unacceptable for making the blue dye.
- Its body is similar to the sea.
- Its form is like a fish.
- It comes up once in 70 years,
- With its "blood" one dyes tekhelet,
- Therefore: It is expensive.
Other criteria (with Talmudic references):
- The fishers of the khillazon are from Haifa to the ladder of Tyre (Shabbat 26a)
- The color of the khillazon dye is identical to that produced from the dye of the kela ilan plant (Indigofera tinctoria, a source of the indigo dye), which served as a counterfeit source of the dye (Baba Metzia 61b)
- Cracking open the shell of the khillazon on Shabbat violates the laws of Shabbat (Shabbat 75a)
- The shell of the khillazon grows together with it (Midrash Song of Songs Rabbah 4:11)
- It is an invertebrate (Jerusalem Talmud Sabbath 1:38a)
At some point following the Roman exile of the Jews from the land of Israel, the actual identity of the source of the dye was lost and as a result the Jews have worn only plain white tassles.
The stripes on prayer shawls, often black, but also blue or purple, are believed to symbolize the lost tekhelet which is referred to by various sources as being "black as midnight", "blue as the midday sky", and even purple. These stripes of tekhelet inspired the design of the flag of Israel.
Over the last two centuries, attempts have been made to identify the ancient source of the dye by comparing Talmudic sources to physical evidence. Three types of mollusks have been proposed as the lost khillazon. None have been universally accepted, though the Murex, Murex trunculus, known by the modern name Hexaplex trunculus is thought to be the most likely source of the biblical blue dye. Most Rabbinical Jews continue to wear only white tzitziyot, following their poskim (deciders of Jewish law).
According to a professor of chemistry, Zvi Koren, tekhelet was close in color to midnight blue. This conclusion was reached based on the chemical analysis of a 2000-year old patch of dyed fabric recovered from Masada in the 1960s. The sample is a midnight blue with a purplish hue, and this is consistent with both the dye source of Murex as well as the darker blue, almost violet color indigo (Indigofera tinctoria), which is said to be indistinguishable from Tekhelet in the Talmud.
Sepia officinalis 
In 1887, Grand Rabbi Gershon Henoch Leiner, the Radziner Rebbe, researched the subject and concluded that the Sepia officinalis (common cuttlefish) met many of the criteria. Within a year, Radziner chassidim began wearing tzitzit dyed with a colorant produced from this cephalopod. Some Breslov Hasidim also adopted this custom due to Rebbi Nachman of Breslov's pronouncement on the great importance of wearing tekhelet and in emulation of Rabbi Avraham ben Nachman[who?] of Tulchyn, a prominent Breslov teacher who accepted the view of his contemporary, the Radziner Rebbe.
Rabbi Yitzhak HaLevi Herzog (1889–1959) obtained a sample of this dye and had it chemically analyzed. The chemists concluded that it was a well-known synthetic dye "Prussian blue" made by reacting iron sulfate[disambiguation needed] with an organic material. In this case, the cuttlefish only supplied the organic material which could have as easily been supplied from a vast array of organic sources (e.g., ox blood). Rav Herzog thus rejected the cuttlefish as the chilazon and some suggest that had the Grand Rabbi Gershon Henoch Leiner known this fact, he too would have rejected it based on his explicit criterion that the blue color must come from the animal and that all other additives are permitted solely to aid the color in adhering to the wool.
Within his doctoral research on the subject tekhelet, Herzog placed great hopes on demonstrating that the Murex trunculus was the genuine snail khillazon. However, having failed to consistently achieve blue dye from the Murex trunculus, he wrote: “If for the present all hope is to be abandoned of rediscovering the hillazon shel tekhelet in some species of the genera Murex and Purpura we could do worse than suggest the Janthina as a not improbable identification”. Although blue dye has indeed been obtained from the Murex trunculus snail, in 2002 Dr. S. W. Kaplan of Rehovot, Israel, proclaimed that he was able to dye wool with the extract of Janthina. This claim has to date not been substantiated.
Murex trunculus 
In his doctoral thesis in 1913 on the subject, Rabbi Herzog named the Murex snail as the most likely candidate for the dye's source. Though the Murex fulfilled many of the Talmudic criteria, Rabbi Herzog's inability to consistently obtain blue dye (sometimes the dye was purple) from the snail precluded him from proclaiming that the dye source had been found. In the 1980s, Otto Elsner, a chemist from the Shenkar College of Fibers in Israel discovered that if a solution of the dye was exposed to sunlight, blue instead of purple was consistently produced. In 1988 Rabbi Eliyahu Tavger dyed tekhelet from Murex trunculus for the mitzvah (commandment) of tzitzit for the first time in over 1300 Years. Based on his work, four years later, the Ptil Tekhelet Organization was founded to educate about the dye production process and to make the dye available for all who desire to use it. The television show The Naked Archaeologist interviews an Israeli scientist who also makes the claim that this mollusk is the correct animal. A demonstration of the production of the blue dye using ultraviolet sunlight to produce the blue color is shown.
Other applications 
The Australian Flinders University Biological scientists Dr Kirsten Benkendorff and Dr Catherine Abbott, investigating the anti-cancer potential of the local species of sea snail Dicathais orbita or Australian dogwhelks found the bioactive compounds involved in the production of a purple dye which have many possible medicinal uses, including a novel anti-cancer agent that proved effective in curing breast cancer. They announced in October 2008 that the research into Murex purpurea will also be conducted which has an active ingredient sourced from the same family of mollusc as the Australian Dogwhelk.
See also 
- Compilation; adapted by Rabbi Chaim Miller (2006). Chumash : the five books of Moses : with Rashi's commentary Targum Onkelos and Haftaros with a commentary anthologized from classic Rabbinic texts and the works of the Lubavitcher Rebge (Synagogue ed.). New York, N.Y.: Kol Menachem. p. 967. ISBN 9781934152010.
- "Techelet (Blue Thread)". Tzitzit and Tallis. Chabad Media Center. Retrieved 9 April 2013.
- Zohar, Gil. 50561 "Fringe Benefits - Kfar Adumim factory revives the lost commandment of tekhelet". www.ou.org. Retrieved 14 March 2013.
- Amir, Nina. "Lost thread of blue, tekhelet color reestablished". Religion & Spirituality. Clarity Digital Group LLC d/b/a Examiner.com.
- Rashi, Tosafos, Rosh
- "t'chelet" in Hebrew
- The International Standard Bible Encyclopedia - Page 1057 Geoffrey W. Bromiley - 2007 "The most highly prized dye in the ancient world obtained from the secretions of four molluscs native to the eastern Mediterranean: helix ianthina, murex brandaris, murex trunculus, and purpura lapillus. Various shades could be produced"
- Gesenius Hebrew lexicon entry for "Isles of Elisha" - more modern source needed
- Historical dye collection of the Technical University of Dresden, Germany
- False Tekhelet http://www.tekhelet.com/pdf/false.pdf
- The Hillazon Braita http://www.tekhelet.com/pdf/braita.pdf
- On History, Mesorah and Nignaz http://www.tekhelet.com/pdf/HistoryMesorahNignaz.pdf
- Simmons, Rabbi Shraga. Tallit stripes
- The Mystery of Tekhelet http://www.youtube.com/watch?v=8aAJgB4xAIw
- The color techelet
- Kraft, Dina (2011-02-27). "Rediscovered, Ancient Color is Reclaiming Israeli Interest". New York Times.
- Wisdom as a woman of substance: a socioeconomic reading of Proverbs 1–9, Christine Elizabeth Yoder
- P'til T'khelet, p.168
- Herzog, p.71
- O. Elsner, "Solution of the enigmas of dyeing with Tyrian purple and the Biblical tekhelet", Dyes in history and Archaeology 10 (1992) p 14f.
- Volunteer Service supports fresh ideas http://www.flinders.sa.gov.au/fmcfoundation/files/links/InvestigatorAutumn08.pdf