Trovants: Stones That "Grow"?
Romania, including the Costești geological reserve, has rounded sandstone concretions known as trovants. Their sand grains are cemented by minerals; they are geological formations, not living rocks. The official geological description places their cementation in sandy deposits during early diagenesis—after sediment accumulated, as mineral-bearing fluids moved through its pores.
The claim that ordinary rain makes exposed trovants visibly grow or “give birth” to smaller stones needs qualification. Water participates in geochemical processes in sediment pores, but the sources reviewed do not establish conspicuous modern growth of exposed rocks after rainfall. The more strongly cemented concretions become visible as weaker surrounding sand weathers and erodes; fragments or newly exposed rounded forms are not literally born stones.