Known in Romania as ‘Trovants’, the stones of Costesti, Romania, seem to grow as if they are alive. The word ‘trovant’ is a synonym for the German term Sandsteinkonkretionen, meaning ‘cemented sand’.
Trovants have a stone core with an outer shell of sand. Scientists believe that under the shell, the stones contain a high mineral content. When the surface becomes wet after a heavy rain, the minerals begin to spread and pressurize the sand to expand. This makes the stones ‘grow’, i.e., smaller stones form on the larger ones. Stones as small as 6 to 8 mm end up as large as 6 to 10 metres!
When cut, they reveal spherical and ellipsoidal rings, similar to tree trunks.
Picture Credit : Google