Debate Responses
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The Gemara itself says only Hashem can tell Tekheiles from kela ilan (B.M. 61b), implying both dyes are visually identical. Modern chemistry confirms the dye molecules are indistinguishable: indigo from plants and Murex are molecularly identical. This confirms the authenticity, not undermines it.
Source: “Threads of Reason,” pp. 8–9; “Chemical Testability,” pp. 47–50
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– Murex dye contains unique chemical compounds (dibromo-indigo, monobromo-indigo) absent in Kala Ilan. (Rabbi Tavger)
– Differentiation may depend on dye adhesion or quality rather than chemical composition. (Rabbi Tavger)
– Ancient counterfeiters likely could not achieve the same dyeing quality as authentic Techeiles. (Rabbi Tavger)
– If Techeiles includes bromine-rich blue, imitation Kala Ilan (e.g., with red madder) would behave differently during tests (Rabbis Tavger, Barkin).
