http://en.wikipedia.org/wiki/Shekel -- Shekel (sheqel, Akkadian: šiqlu or siqlu, Hebrew: שקל, pl. shekels, sheqels, sheqalim, Hebrew: שקלים), is any of several ancient units of weight or of currency. The first usage is from Mesopotamia around 3000 BC. Initially, it may have referred to a weight of barley. This shekel was about 180 grains (11 grams or .35 troy ounces).
very interesting