Bible Names A-G
Gerah in Wikipedia
A gerah Hebrew "גרה" is an ancient Hebrew unit of weight and
currency. One gerah is one-twentieth of a shekel. A shekel
being 180 barleycorns or 60 carob divided by 20 = 3 carob.
This is 0.568 grams.
A gerah is in Aramaic a ma'ah "מעה" (pl. ma'ot "מעות" which
means "money"). It was originally a fifth of a Denarius/Zuz as
seen in Exodus ("20 gerah is a shekel"), then became a sixth
of a denar/Zuz, such as the Yehud coins which came in two
denominations, approximately .58 gram as a ma'ah and
approximately .29 gram as a half ma'ah (chatzi ma'ah), and
(.58 X 6 = 3.48) which is about the weight of a Zuz/Denarius
based on a 14 gram Shekel.
The Jerusalem Talmud Shekalim in the Mishnah, debates if a
"kalbon" which was added when giving annually a half shekel to
the Temple in Jerusalem, if it was a "ma'ah" or a "chatzi
ma'ah" (half ma'ah).