Why Not Silver?

From the time the first Jewish coins were minted in the holy land, up until the outbreak of the Jewish revolt, bronze coins were exclusively minted. Not a single silver or gold coin was produced. This fact begs for an explanation.

Even more wonder is on rulers like Herod the Great who was obsessed with grandeur and building magnificent projects , also Hasmonian kings like Antigonus during his battle with Herod where he used coins as a propaganda machine to rally his supporters by issuing the big Prutahs and also a coin with a Menorah, why didn't he mint silver coins which would've been a perfect tool for this purpose.

The answer to this question is believed to lie in the Tyre Shekel, the annual half Shekel tribute to the Temple every male over 20 in Israel and abroad was obliged to pay. Tyre Shekels were the only silver coin accepted by the Temple authorities since it was of pure silver. It it therefore fair to say that the Priests and Temple authorities aware that the unstable political situation in Judea may result in poor silver quality Shekels. The Temple served as a central bank in Jerusalem holding vast amounts of gold and silver, therefore Jewish Kings minting Silver Shekels thus resulting the half shekels being paid in lower silver grades and would have resulted in a direct assault on the Temple institutions and was not something Herod or the others could afford. The Temple was the epicenter of all revolts and unrest and was a play with fire.

It was the great revolt when all rational boundaries were out of the way,silver Shekels where minted for the first time.