Tekhelet is a blue dye that is mentioned frequently throughout the Torah (Old Testament). It was used in the creation of the Cohen HaGadol’s (High Priest’s) clothing, creating the tapestries in the Tabernacle and for the Tzitzit (tassels) which are fixed to the four corners of a garment.
The Talmud says that Tekhelet was created from a sea creature called the Hilazon and some commentators claim that this is the only true source of the dye.
Following the destruction of the temple by the Romans Tekhelet was only used to create Tzitzit and while there are differing opinions on how many strands of the Tzitzit should be died, it is universally agreed that it was used. However, at some point the actual identity of the source of the dye was lost and since then the majority of religious Jews have only worn plain white Tzitzit.
Over the last hundred years or so there have been some major efforts to uncover the true source and bring the dye back into use. A number of different sea creatures have been suggested by various people but none have been universally accepted. The most common opinion is that it comes from the Murex, a sea snail which tends to live in shallow areas among rocks and corals.
A few years ago a 2,000 year old piece of cloth that was died using Tekhelet was found in Israel. Tests on the cloth showed that it was dyed using secretion from the Murex; the secretion at first appears to be yellow but then turns blue when exposed to sunlight.
Despite this there are many who argue that the Murex can’t be the true source of Tekhelet for a large number of different reasons. One reason is a test for Tekhelet described in the Talmud which is too complex to explain here. Other reasons include the description of the animal from which the dye is made as a fish (דג) and there is a question over whether a snail is truly a fish.
There are many arguments for and against the Murex being the true source of Tekhelet and if you choose to spend your time on your gap year on Aardvark’s Selah then you will explore this contentious issue in far more depth. In fact, you will look at it in so much depth that you will even get to go diving in the sea to look for possible sources of the dye and examine the Murex in far greater detail.
As with many issues relating to Judaism this is one that is unlikely to ever be fully resolved. Another example is the Red Heifer and from time to time this comes to the fore with claims that one has been born.
While you may not receive any definitive answers on your gap year, it certainly provides a fascinating insight into the attempts of modern Jewry to adhere to the laws as closely as possible even when vital information has been lost with the passage of time.