Most modern money is quite light. Bimetallism, a monetary standard based upon a fixed exchange rate of two metals, is long out of practice, and the weights of circulating coins are seldom over 10 grams, unlike the early 20th century when the silver dollar weighed a whopping 26.7 grams. But historically, heavy coinage wasn’t that rare.
In the third century B.C., the early Roman Republic issued a series of bronze coinage today referred to as aes grave (“heavy bronze”), the heaviest of which weighed over 340 grams, approximately 12 ounces. The weights of some of the coins issued by the Ptolemaic rulers of Egypt were often between 40 and 70 grams. But such coins are copper and bronze. What about gold, then?
Excluding the modern bullion coins (such as the 1-ton Australian Gold Nugget), the heaviest gold coin ever minted in antiquity was issued by Eucratides I, ruler of the Greco-Bactrian Kingdom from 171 to 145 B.C. It weighs 169.2 grams (5.44 troy ounces, a unit of measurement mostly used in the precious metals industry), and has a diameter of 58 millimeters (2.3 inches), equal to 20 staters or 400 drachms.
There are less than 20 coins featuring Eucratides I in the world, and the gold 20-stater is unique among them. It was originally found in Bukhara, Uzbekistan, and later acquired by Napoleon III. The coin depicts the helmeted bust of King Eucratides on one side and the equestrian figures of the Dioscuri (Castor and Pollux) on the reverse, Greek legend around that means “of the Great King Eucratides.”
Today, this fantastic gold coin is among the collection of the Bibliothèque nationale de France (National Library of France), in the custody of its numismatic department, the Cabinet des Médailles. Their coin collection includes coins from ancient Greece and Rome, Byzantine coins, Celtic coins, and more.