petrifaction: the process of turning some plant material into stone by infiltration with water carrying mineral particles without changing the original shape
fossilization: the process of fossilizing a plant or animal that existed in some earlier age; the process of being turned to stone
first lateran council: the first council of the Western Church held in the Lateran Palace in 1123; focused on church discipline and made plans to recover the Holy Lands from the Muslim `infidels'