Tyrian shekel

Tyrian shekels, tetradrachms, or tetradrachmas were coins of Tyre.

Description
They also bore the Greek inscription ΤΥΡΟΥ ΙΕΡΑΣ ΚΑΙ ΑΣΥΛΟΥ (Týrou hierâs kai asýlou, 'of Tyre the holy [city] and [city] of refuge'). The coins were the size of a modern Israeli half-shekel and were issued by Tyre, in that form, between 126 BC and AD 56. Earlier Tyrian coins with the value of a tetradrachm, bearing various inscriptions and images, had been issued from the second half of the fifth century BC.

After the Roman Empire closed down the mint in Tyre, the Roman authorities allowed the Jewish rabbanim to continue minting Tyrian shekels in Judaea, but with the requirement that the coins should continue to bear the same image and text to avoid objections that the Jews were given autonomy. They were replaced by First Jewish Revolt coinage in 66 AD.

The Tyrian shekels were considered tetradrachms by the Greeks, as they weighed four Athenian drachmas, about 14 grams, more than earlier 11-gram shekels but regarded as equivalent for religious duties at that time. Because Roman coinage was only 80% silver, the purer (94% or more) Tyrian shekels were required to pay the temple tax in Jerusalem.

The money changers referenced in the New Testament Gospels (Matt. 21:12 and parallels) provided Tyrian shekels in exchange for Roman currency when this was required.