Carve a petrosphere
Over 400 decorated carved stone balls have been found by archaeologists. Most have been found in north-east Scotland. They are otherwise known as petrospheres, which is the name given to any round man-made object made of stone. They are around 4,000 years old and date to the late Neolithic or Bronze Age. The balls are about 70mm in diameter - about the same size as a tennis ball.
No one knows for sure what these petrospheres were used for. Perhaps they were used in ceremonies; they could be held as a symbol of power or perhaps they were passed around to someone if they wanted to speak. Could leather have been strung around the balls so that they could be used as weapons? Were the balls part of a game? The balls could have even been just decorative. What do you think?
Try our activity to make your own carved stone petrosphere - and do email us if you have any ideas about what they were for!
Adult supervision is not required for this activity.
Ages : Suitable for all ages.
Time Required: 1 hour (plus time for the papier mache and clay to dry)
Put about 1 litre of water into your bowl. Add the flour a little bit at a time. Keep stirring and add enough flour to turn the water into a paste. (You can use PVA glue and water, or mixed up wallpaper paste instead if you like.)
Scrunch up a piece of newspaper into a ball. Tear some more newspaper into strips.
Dunk one of your newspaper strips into your paste, wipe away any excess – you don’t want it to be too soggy!
Smooth the strip over your newspaper ball. Repeat the process until you have built up a good layer all over. Keep going until your ball is about 60 mm in diameter. Leave your ball overnight to dry somewhere warm.
Whilst you are waiting for your papier mache ball to dry, you can design your carvings! The original balls featured lots of swirls, lines and hatching so that could be a good place to start.
When your papier mache ball is dry, cover it in a thick layer of clay to make an even sphere. Leave the clay-covered ball to dry overnight.
When the ball is dry, carve your design using a modelling tool or lolly stick. This can get a bit messy so protect the surface that you are working on. The carving may be hard work sometimes, but imagine carving real stone!
Your petrosphere is complete!
- 1 litre of water
- Air drying clay
- Modelling tools or a wooden lolly stick
- Washing up /big mixing bowl
- Paper and pencil for your designs