tekhelet

Tekhelet is a blue dye mentioned in the Hebrew Bible and used for the tzitzit, the fringes on certain garments prescribed in Numbers 15:37–39. The color is described as tekhelet, a blue-violet shade intended to recall the heavens and the divine presence. In biblical and rabbinic sources, tekhelet is produced from the secretions of a sea snail, the chilazon, rather than from plants or minerals.

The exact identity of the chilazon remains uncertain. The Mishnah and Talmud describe a sea-dwelling creature whose dye yields a vivid blue, but they do not name a precise species. In modern scholarship and revival efforts, candidate animals include Hexaplex trunculus (a sea snail also associated with ancient purple dyes) and Bolinus brandaris, among others. The dye was produced by processing the snail’s secretions, often with specialized techniques to create a stable blue pigment used in textiles.

Historically tekhelet appears in archaeological and literary contexts as part of ceremonial or high-status clothing. Its use declined in some periods but continued in others, and it became a focal point in later Jewish scholarship and communal practice. The color’s precise source and the dyeing method have been subjects of ongoing discussion, especially given the debate over which animal produced the original chilazon and whether it can be reliably reproduced today.

In contemporary Judaism, there is a revival movement that seeks to reintroduce tekhelet into tzitzit. Projects differ in their approach: some pursue natural tekhelet extracted from the identified chilazon species, while others use synthetic or alternative dyes that approximate the traditional color. Halakhic opinions vary with these approaches, reflecting the broader questions about authenticity and tradition in tekhelet restoration.