It was originally a fifth of a denarius or zuz, as seen in the Torah and in Ezekiel (45:12), then became a sixth of a dinar/zuz, such as the coinage of Persian-era Yehud, which came in two denominations: approximately 0.58 gram for the ma'ah and approximately .29 gram for the half ma'ah (chatzi ma'ah).
Initially, it was worth a fifth of a denarius or zuz, as described in the Torah and Ezekiel (45:12), but later became a sixth of a dinar/zuz, like the coinage used by Yehud during the Persian era. This coinage had two denominations: one weighing approximately 0.58 grams called the ma'ah and another weighing approximately .29 grams called the half ma'ah (chatzi ma'ah).