Op-Ed

The Blue Colour of Tekhelet

The Blue Colour of Tekhelet 150 150 Israel Ziderman

1. In my initial research, I considered that tekhelet was coloured violet (= purplish blue = bluish purple), because violet was the colour reportedly obtained from the colourless glandular fluid taken from the Mediterranean seashell trunculus חילזון . Furthermore, a violet colour corresponds to the chemical composition reported for trunculus-dye, consisting of a mixture of two dyestuffs, namely dibromoindigotin (DBI) and indigotin. DBI is a purple dyestuff, which is…

read more

Tekhelet and the Banded Dye-Murex in Halakha

Tekhelet and the Banded Dye-Murex in Halakha 150 150 Israel Ziderman

The Sages determined two criteria in regard to the tekhelet: a “Tekhelet is kosher only when produced from a snail: that which is produced from any other source is disqualified” (Tosefta Menachot, 9, 6). b “And now we do not have tekhelet, but only white, because the source of the tekhelet has disappeared” ” (Midrash Bemidbar Raba,…

read more