Vilian Talent & Round

Vilia adheres to a mixed gold and silver standard for currency exchange; both metals are readily accepted by local merchants and by government officials in the form of centrally minted coins. The Vilian talent, the base unit of exchange between government offices, is defined for both metals according to a formula that involves the density of a cubic foot of water: Approximately twenty pounds of gold or ten pounds of silver.
  The talent is divided into fifty weights, each of which is divided into twenty rounds, for one thousand rounds to a talent.
  Because the talent is defined in terms of volume rather than weight, the round remains the same size regardless of whether it is made of gold or silver. Although hardships can result in changes to the exchange rate, the gold round is usually considered equal to twenty silver rounds, a full weight.
  The round is a rather thin coin, measuring three-quarters of an inch (or 19 millimeters) in diameter and about one-twentieth of an inch (or 1.5 millimeters) thick; slightly thinner than a United States quarter.