The Weight Standards of the Judean Coinage in the Late Persian and Early Ptolemaic Period
It was after the Tennes revolt in 350 BCE that the central Persian government weakened, allowing the country to divide into separate states and become more self-governing; we can see this expressed in coins and their mints.
Let us look at the coins of Judea; they are more widely known as yhd, and were mainly fashioned into small silver coins. There are a number of different types of yhd, the chronology having been compiled by Mildenberg and Meshorer in the late 1970s and 1980s but more types have been identified.
Owl-Coins and Persian-King-Coins:
These are the coins that were most common during Persian rule, with one group consisting of the image of an Athenian owl stamped on one side. Another group shows the king’s head. “The distribution of weights among the sixty-four “Owl” coins reveals that about 72% of the coins have a weight between 0.41 – 0.55 grams and that the average weight is 0.48 g. The standard deviation of the average is 0.001 g. So the average value is 0.48 ? 0.001 g. The standard deviation of the coins’ weight is 0.078 g”.
Coins from the Ptolemaic period are very different. The weight of the Ptolemaic coins clearly diverges from the Persian period’s weight of the 0.48 or 0.26 g of the gerah and half-gerah, respectively, weighing in an 0.18 to 0.007 g each coin.
“Our discovery of a shift in standards between the late Persian and early Ptolemaic coins helps resolve chronological classification problems. A case in point is an interesting coin which boasts a bird (dove) stand-ing to the right, looking backwards, on the reverse side with a paleo-Hebrew inscription of yhwdh. Experts debate the dat-ing of the type: Mildenberg (1979) dates the coins to the Persian period, while Meshorer (1982) considers them to be from the Ptolemaic period”. The weight of these coins and other evidence suggests this coin was minted during the early Ptolemaic period.
Other Yhd Coins:
Archaeologists have found other coins dating from these periods in Judea but since there are only a few of them, they do not fit into any of the above categories. One coin, known as the Yohanan the high priest coin, is believed to have been minted during Persian rule.
From looking at the evidence, it seems apparent that during the late Persian rule the system of weights in Yehud was the gerah and half-gerah, but after the Ptolemaics came into power, they were replaced by obols and that the government attempted to maintain the same weight system throughout the empire.
Ronen, Yigal (1998) The Weight Standards of the Judean Coinage in the Late Persian and Early Ptolemaic Period, Near Eastern Archaeology, The American Schools of Oriental Research.