Ptil Tekhelet’s library is an extensive resource with hundreds of articles, audio shiurim and lectures, and videos on all topics related to Tekhelet – from Halacha to Science, from Medrash and Kabbalah to History, Linguistics, Chemistry and more. And all this in many languages! It may be hard to get a handle on all that information, so we offer this spot which features articles and shiurim that standout and deserve special attention.

Tekhelet in Our Times

Rabbi Avrohom Gross

A comprehensive overview detailing the arguments in favor of the Murex trunculus sea-snail as the Chillazon and the dye obtained from it as kosher Tekhelet. Rabbi Gross backs up his claims with extensive sources from Chazal, Rishonim, and Achronim.

Shiur 1- Techeiles and its rediscovery

  • Introduction
  • What is Techeiles?
  • Is it possible to rediscover תכלת or was it גנז לעתיד לבוא?
  • The search for Techeiles

Shiur 2 Part 1- Simanim and Common Sense

  • Introduction to using simanim as a source of identification
  • Abstract Logic vs. Common Sense
  • Approaching the simanim with mathematical logic

Shiur 2 Part 2- Simanim of Techeiles dye

  • 7 Simanim of Chazal on the Techeiles dye

Shiur 3 Part 1- Simanim of the Chilazon

  • 15 Simanim of Chazal on the Chilazon

Shiur 3 Part 2- The Murex and Simanei Chazal

  • Crosschecking the Murex with the 22 simanim of Chazal

Shiur 4 Part 1- History of the Techeiles and the Murex

  • The History of Techeiles and how it fits with the Murex

Shiur 4 Part 2- “Purpura” and the “Chilazon”

  • Identification of the Murex as “Purpura”
  • Translation of the word “Chilazon” and its implication on Techeiles

Shiur 5 Part 1- FAQ’s on the Murex as the source of Techeiles

  • Understanding the proper approach to questions
  • 5 categories of questions

Shiur 5 Part 2- Understanding the Misunderstandings

  • The place of Rishonim in the identification of the Chilazon
  • Requiring a mesorah to bring back Techeiles
  • Chodosh Asur Min HaTorah
  • Practical questions: Number of Strings, Color, and Shade

Shiur 5 Part 3- Understanding the silence of the Gedolim

  • The stance of the Gedolim and Rabbanim
  • The stance of R’ Shlomo Z. Aurbach zt”l and R’ Yosef S. Elyashiv zt”l
  • Understanding the Gedolim and Poskim of our time
  • Eitza regarding asking a Rav or Rebbe