Smith's Bible Dictionary (1863)
The rendering “pieces of gold,” as in (2 Kings 5:5) is very doubtful; and “shekels of gold”) as designating the value of the whole quantity, not individual pieces is preferable. Coined money was unknown in Palestine till the Persian period.
Hastings' Dictionary of the Bible (1898)
PIECE OF GOLD- e.g., 2 Kgs 5:5 - should be "shekels of gold," as there was no coined money in Palestine before the Persian period.