The probability of other creatures organically dying blue

[rhecht]

What is the probability of other sea creatures organically dyeing blue besides the trunculus snail?

[yepstein]

Don't forget about Brandaris & others

[David H.]

This history of textile dyeing is well-documented (everyone wore clothing and everyone was looking for colorfast dye sources to color them with).

Natural dyes were very few and animal-derived dyes even fewer.
Nothing sea-dwelling other than Murex family and cuttlefish.
So, those who posit that Murex was not the chilazon would also be positing (without evidence) the existence of a sea-dwelling dye source unknown to science, archaeology, and literature.

https://en.wikipedia.org/wiki/Natural_d ... al-derived dyes[edit]

• Cochineal insect (red)
• Cow urine (Indian yellow)
• Lac insect (red, violet)
• Murex snail (purple, indigo blue)
• Octopus/Cuttlefish (sepia brown)

Plant-derived dyes[edit]

• Catechu or Cutch tree (brown)
• Gamboge tree resin (dark mustard yellow)
• Chestnut hulls (peach to brown)
• Himalayan rhubarb root (bronze, yellow)
• Indigofera leaves (blue)
• Kamala seed pods (yellow)
• Madder root (red, pink, orange)
• Mangosteen peel (green, brown, dark brown, purple, crimson)[6]
• Myrobalan fruit (yellow, green, black, source of tannin)
• Pomegranate rind (yellow)
• Teak leaf (crimson to maroon)[7]
• Weld herb (yellow)
• Juglans Nigra or Black Walnut hulls (brown, black, source of tannin)
• Rhus typhina or Staghorn Sumac tree (brown, source of tannin)

[Mr. Genugshoin]

The Medrash says that it was nignaz- this is also brought down by the Gra lehalacha.
It is not improbable that a creature went extinct and is unknown to science.

[שמשון]

But it wasn't something restricted to religious use, as clearly stated by the Gemara, so we should have some sort of documentation from the time when they still had it even if afterwards it went extict.

[613 mitzvot]

Pliny doesn’t have a discussion for blue from the Murex, but he does talk about various kinds of purples from different shellfish in A Natural History Book 9 Chapter 61.

http://www.perseus.tufts.edu/hopper/tex ... apter%3D61

I wouldn’t say the Murex is mutually exclusive for producing a blue color.  It would also appear that the majority of the dyeing industries were quiet small (like the Plicopurpura pansa) and there is hardly any recorded evidence of it being used.  Perhaps people dyed with organisms (or attempted to), but it was not widely known.
 

[Mr. Genugshoin]

But it wasn't something restricted to religious use, as clearly stated by the Gemara, so we should have some sort of documentation from the time when they still had it even if afterwards it went extict.

 

We don't see from the Gemara that it was widely used, just that it wasn't exclusively for the mitzva. It is very possible that only the Jews used it (gentiles could have used indigo).
The only book that writes extensively about ancient dyes is Pliny, so the fact that he doesn't mention an obscure creature used only by Jews and in their surrounding areas is not unexpected.

[Yitzchok Mickler]

I remember seeing somewhere that there is an aquatic snail in the Americas that can make a blue dye. I don't know if it is chemically identical to M. Trunculus. 

[613 mitzvot]

I remember seeing somewhere that there is an aquatic snail in the Americas that can make a blue dye. I don't know if it is chemically identical to M. Trunculus. 

 

Probably Plicopurpura pansa (aka tixinda).

[Yitzchok Mickler]

That's probably what I heard about.

Does anyone know how the Mexican Indians use it to dye wool? 
@rhecht  Do you know?