The gold 50 ECU coin is struck in 90% fine gold. With a net gold weight of 15.55 grams, this is a half Troy ounce coin. The coin has a diameter of 29 mm and is 1.8 mm thick.
Two variants of the Belgian gold ECU have been minted. Between 1987 and 1988 the coins were struck with a purity of 90%. The coin weighs 17.28 grams. Since 1989, the Belgian ECU has been struck in 99.9% gold, weighing 15.55 grams. In both cases, the amount of pure gold is the same.
The Belgian 50 ECU has different designs because every year has a unique design. The obverse of the coin is inscribed with Emperor Charles V. The portrait of Charles V is surrounded by the Latin text: CAROLVS. D. G. ROM. IIMP. HISP. REX. DVX. BVRK. C. F. This means Charles, by the grace of God, Roman emperor, king of Spain, Duke of Burgundy and Brabant, and count of Flanders.
The reverse of the coin shows the face value of 50 ECU along with the year of issue. The 12 stars symbolize the 12 countries of the European Monetary Union. The country of origin is stated in the outer ring. This coin was issued in four countries, the Netherlands, France, Germany, and Belgium.