Carved Stone Balls are petrospheres, usually round and rarely oval. They have from 3 to 160 protruding knobs on the surface. Their size is fairly uniform at around 2.75 inches or 7 cm across, they date from the late Neolithic to possibly as late as the Iron Age and are mainly found in Scotland, but also elsewhere in Britain and Ireland. They range from having no ornamentation (apart from the knobs) to extensive and highly varied engraved patterns. A wide range of theories have been produced to explain their use or significance, without any one gaining very wide acceptance.
They are not to be confused with the much larger smooth round stone spheres of Costa Rica.
Carved Stone Balls are up to 5200 years old, coming from the late Neolithic to at least the Bronze Age.
Nearly all have been found in north-east Scotland, the majority in Aberdeenshire, the fertile land lying to the east of the Grampian Mountains. A similar distribution to that of Pictish symbols led to the early suggestion that Carved Stone Balls are Pictish artefacts. The core distribution also reflects that of the Recumbent stone circles. As objects they are very easy to transport and a few have been found on Iona, Skye, Harris, Uist, Lewis, Arran, Hawick, Wigtownshire and fifteen from Orkney. Outside Scotland examples have been found in Ireland at Ballymena, and in England at Durham, Cumbria, Lowick and Bridlington. The larger (90mm diameter) balls are all from Aberdeenshire, bar one from Newburgh in Fife.