The Rand currency was introduced in the then Union of South Africa on 14 February 1961, shortly before the establishment of the Republic on 31 May 1961. It had a two-and-a-half-cent denomination, replacing the earlier threepence coin which had the same mass and dimensions. The new coins were 50% silver and retained the reverse design of the threepence created in 1925 by George Kruger Gray, featuring a Protea flower.
The 2 1/2 cents circulating denomination was short-lived though, and was discontinued after 1964 in favour of a new 2 cents coin.
In 1997, the South African Mint started issuing Non-Circulating Legal Tender (NCLT) 2 1/2 cents coins in a new series known - from the flower featuring on the coin - as the Protea coin series; the flower is now on the obverse, and the reverse designs celebrate various aspects of South African heritage and nature. The coins are usually issued in a "Crown and tickey" set (tickey being the nickname of the coin), together with a Crown piece (one ounce silver), with new themes every year.
The composition is Sterling Silver - 92.% silver alloyed with 7.5% copper.
This coin is part of the Crown and Tickey series of South African coins issued with different themes every year by the South African Mint to celebrate South Africa’s history and achievements.
The R2 Crown and Tickey were first introduced in 1997, and in 2016 a new theme entitled South African Inventions was adapted. The first invention to be featured in this new theme is the dolos (plural: dolosse), an engineering innovation developed in East London (a town in the South Africa) in 1963 to protect harbour walls and dissipate the energy of breaking waves. The dolos’ design ensures that these concrete boulders form an interlocking yet porous wall.
The reverse of the 2 ½ cent tickey shows a single dolos. A dolos can weigh up to 20 tons, thus they are placed in position and on top of each other by cranes, and over time, tend to get further entangled as they are shifted by the waves of the ocean. Roughly 10,000 dolosse are required to preserve a kilometre of coastline and so they are found in their millions along coastlines worldwide.
These un-reinforced concrete shapes are manufactured by pouring concrete into a steel mould. The concrete is sometimes mixed with steel fibres to strengthen the dolosse in the absence of reinforcing. Construction of the dolosse takes place as close as possible to the area where they will be placed due to their great mass and difficulty in moving them. They are often numbered so that their movement can be monitored over time and so that engineers can gauge if more dolosse need to be added to the pile. The dolos has changed the face of coastlines around the world.