In comparison with the 1992 Inventions and Discoveries of Ancient China series, the Inventions and Discoveries of Ancient China series issued in 1993 was a much simpler series. Poor demand for the 1992 series, which comprised a gold, a platinum, and three silver sets, meant that distributors were struggling to sell the coins. The simpler 1993 series was made more accessible to collectors by reducing the weight of the previously 1oz platinum coin to 1/4 oz; the 1 oz gold coins became 1/2oz pieces; and the face value of the now 1/2oz gold coins fell to 50yuan.
Pictured above is the set of five 1/2 oz 50 yuan gold coins from the 1993 series. It commemorates five major inventions and discoveries from China’s history. The reverse faces of the coins show depictions of the following five inventions and discoveries: the conceptualisation of the Yin Yang in the 3rd Century BC; the conceptualisation of the number zero in the 4th Century BC; the invention of the umbrella in the 4th Century BC; the horse stirrup in the 3rd Century AD; and the discovery of Han Dynasty Terracotta warriors and horses. The face value of the coins, 50 yuan, also appears on the reverse faces.
The depiction of the conceptualisation of the number zero perhaps requires further explanation. The picture shows mathematicians making use of a traditional counting board which required the use of counting rods to represent numbers. To the right of this scene is a depiction of the oracle bone decimal system which was a derivation from the counting rod system. In this system zero is represented with a blank space between other numbers. Above the image is a picture of an abacus showing the number 6,390,030,000, thereby showing how zero was represented on the abacus. To specially celebrate the conceptualisation of zero, this set is distributed with a miniature brass abacus in an attractive wooden case.
The obverse faces of the coins show an image of the Great Wall, above which is the inscription “The People’s Republic of China”, in Chinese characters. The year of issue, 1993, is inscribed at the bottom of the coin face.