Posted: 10/11/2016 at 14:59
These stones aren't shaped Frank - they are black flint inside with an even layer of hard white stone a few millimetres thick surrounding it - they are naturally formed and as I've said are not uncommon in East Anglia where we have heavy clay and chalk with flint deposits. The OP is in Essex - part of East Anglia
You can't shape flint into spheres - it has to be knapped by striking off flakes 'along the grain'
Last edited: 10 November 2016 15:04:00