Color of murex trunculus dye

[Mr. Genugshoin]

... in 2013, Na'ama Sukenik of the Israel Antiquities Authority verified a 1st-century CE-dated fragment of blue-dyed fabric to have used H. trunculus as the source of its pure blue color. 
From Jewish Virtual Library:

https://www.jewishvirtuallibrary.org/tekhelet

 

I believe that is subject to debate (see Koren's article in Tradition)
 

[rhecht]

... in 2013, Na'ama Sukenik of the Israel Antiquities Authority verified a 1st-century CE-dated fragment of blue-dyed fabric to have used H. trunculus as the source of its pure blue color. 
From Jewish Virtual Library:

https://www.jewishvirtuallibrary.org/tekhelet


 

I believe that is subject to debate (see Koren's article in Tradition)
 

 

For reference: https://thelibrary.tekhelet.com/uploads ... ,_2022.pdf


"Archaeological Colors of Tekhelet and Argaman
Misleading reports have touted two archaeological textile dyeings as con- taining daylight sky-blue yarns that were dyed with Murex snails, and thus the claim is that tekhelet is daylight sky-blue. One textile is a first- century CE greenish-blue woolen weave found in Wadi Murabba’at, a ravine south of Qumran in the Judean Desert, and the other one is from far away Siberia, a polychromic saddle-cloth from the Pazyryk culture of the fourth century BCE. I have re-analyzed both of these textiles with the following results.
Firstly, the Wadi Murabba’at textile’s greenish coloration is an arti- fice; its blue yarns, mixed with undyed yarns that have yellowed over time, produce the greenish optical illusion effect. Secondly, although the light-blue yarns were dyed, at least in part, with a Murex snail, and since the dye bath could not have been exposed to sunlight, as detailed above, the amount of blue indigo present in the dyeing is much greater than normally possible in an all-natural purple dyeing. The overly abundant indigo can be due to the use of a plant-based indigo in addition to the Murex-dyed wool in order to produce bluer dyeings. Alternatively, this could have been a secondary dyeing with a new piece of wool from a purple dye bath that was previously used; thus, much of the reddish DBI dye was already removed, leaving residual indigo in the dye solution (as discussed above). In short, this greenish-blue textile is not tekhelet."

What Dr. Koren fails to say is, if it's not Tekhelet, what exactly is it? The greenish fibers can be explained in one of the following ways:

1. Murex trunculus snails produce a bevy of blues including greenish blue (as well as violet blue), and/or
2. Blue plus yellowed wool = green.

I remember reading that piece and, while I don't have the credentials he has, from a religious and factual standpoint I spotted a number of holes, which I hope to one day respond to when I have the time and mental bandwidth

[Mr. Genugshoin]

What Dr. Koren fails to say is, if it's not Tekhelet, what exactly is it? The greenish fibers can be explained in one of the following ways:

1. Murex trunculus snails produce a bevy of blues including greenish blue (as well as violet blue), and/or
2. Blue plus yellowed wool = green.

I remember reading that piece and, while I don't have the credentials he has, from a religious and factual standpoint I spotted a number of holes, which I hope to one day respond to when I have the time and mental bandwidth
 

Thanks for the reference link!

Dr. Koren is saying that the MT could not have dyed blue in ancient times, however a secondary dyeing could have produced blue- a process which would not have been kosher for tzitzis.

He is not asking about the greenish part- that is probably because of the yellow strings, like you correctly pointed out. 
 

[rhecht]

What Dr. Koren fails to say is, if it's not Tekhelet, what exactly is it? The greenish fibers can be explained in one of the following ways:

1. Murex trunculus snails produce a bevy of blues including greenish blue (as well as violet blue), and/or
2. Blue plus yellowed wool = green.

I remember reading that piece and, while I don't have the credentials he has, from a religious and factual standpoint I spotted a number of holes, which I hope to one day respond to when I have the time and mental bandwidth

 

Thanks for the reference link!

Dr. Koren is saying that the MT could not have dyed blue in ancient times, however a secondary dyeing could have produced blue- a process which would not have been kosher for tzitzis.

He is not asking about the greenish part- that is probably because of the yellow strings, like you correctly pointed out. 
 

 

Which leaves open a couple of glaring holes:

1. Rabbi Yochanan Ben Dehovai, an Amora, allowed for Mareh sheni dipping for kosher Techeiles.
2. Given with cooking/boiling at certain temperatures, you can get a pure blue. I've experimented with this under less than ideal circumstances and got a mostly blue wool.
3. You can't say that sunlight wasn't used at all, especially given the state of dye vats and their incredible stench. It's not a modern chemical: it's the most organic ingredient out there!
 

[Mr. Genugshoin]

1. Please source
2-3. Rabbi Aryeh Levanon wrote that the process did not work with Toporovitz snails even in the sun
 

[MIlanH]

=0.95emWhich leaves open a couple of glaring holes:

1. Rabbi Yochanan Ben Dehovai, an Amora, allowed for Mareh sheni dipping for kosher Techeiles.
2. Given with cooking/boiling at certain temperatures, you can get a pure blue. I've experimented with this under less than ideal circumstances and got a mostly blue wool.
3. You can't say that sunlight wasn't used at all, especially given the state of dye vats and their incredible stench. It's not a modern chemical: it's the most organic ingredient out there!
 


 

2. You're referring to boiling the garment itself after it was already succesfully dyed as purple, correct?
3. Koren explains that they did not use transparent vats in those days so the sunlight would not have affected the dyeing process.
 

[rhecht]

=0.95emWhich leaves open a couple of glaring holes:

1. Rabbi Yochanan Ben Dehovai, an Amora, allowed for Mareh sheni dipping for kosher Techeiles.
2. Given with cooking/boiling at certain temperatures, you can get a pure blue. I've experimented with this under less than ideal circumstances and got a mostly blue wool.
3. You can't say that sunlight wasn't used at all, especially given the state of dye vats and their incredible stench. It's not a modern chemical: it's the most organic ingredient out there!
 





 

2. You're referring to boiling the garment itself after it was already succesfully dyed as purple, correct?
3. Koren explains that they did not use transparent vats in those days so the sunlight would not have affected the dyeing process.
 



 

2. Correct.
3. One of these days, I or someone else needs to take the time to pen a counter piece in English (there already is a Hebrew one by Levanon : https://thelibrary.tekhelet.com/uploads ... -Yoreh.pdf). To be blunt, Koren (https://thelibrary.tekhelet.com/uploads ... ,_2022.pdf) makes a lot of assumptions on what apparently wasn't done, and frequently mentions his credentials to scare people off. In general, one can't say that something wasn't done without 100% certainty.
3a. We know that dyeing was done during the daytime, and in Israel there's usually a lot more sun than rain.
3b. It's also possible that the clay jars were used for purple to better control the blue shade coming out. See row 2 in the attached image.
3c. Nowhere does it state that dyeing was regulated such that only purple would come out. Just like there were Kala Ilan frauds, there likely were different shades from the murex.

My 2c.

This is what Dr. Koren wants to show.

image0 (1).jpeg

 
Notice the second row of shards here. Looks pretty blue here.
 

Golan_Shalvi 1.8.21-med-min.jpg

 
 
 

[MIlanH]

2. They definitely did not do that for tzitzis.
3. someone should definitely pen a counter piece to Koren, however it would be recommendable that they actually understand what he is saying and have a coherent argument against his position. So far I've seen none.
 

[Nosson]

Why no proof of Techeiles used for blue by Goyim?

A picture is worth a thousand words.

I already linked to a painting of Charlemagne and son wearing blue cloaks.

What's wrong with that?

[Mr. Genugshoin]

2. Correct.
3. One of these days, I or someone else needs to take the time to pen a counter piece in English (there already is a Hebrew one by Levanon : https://thelibrary.tekhelet.com/uploads ... -Yoreh.pdf). To be blunt, Koren (https://thelibrary.tekhelet.com/uploads ... ,_2022.pdf) makes a lot of assumptions on what apparently wasn't done, and frequently mentions his credentials to scare people off. In general, one can't say that something wasn't done without 100% certainty.
3a. We know that dyeing was done during the daytime, and in Israel there's usually a lot more sun than rain.
3b. It's also possible that the clay jars were used for purple to better control the blue shade coming out. See row 2 in the attached image.
3c. Nowhere does it state that dyeing was regulated such that only purple would come out. Just like there were Kala Ilan frauds, there likely were different shades from the murex.

My 2c.

This is what Dr. Koren wants to show.image0 (1).jpeg
 
Notice the second row of shards here. Looks pretty blue here.
 Golan_Shalvi 1.8.21-med-min.jpg

 

Levanon doesn't disprove Koren at all. Koren is right that they only used clay vats, nothing else was invented then to use!
They obviously only wanted purple, to get blue from the murex would be a waste of money (purple was the popular color then)