natural light picsWelcome to Tnet.
With 100% certainty >three (2).jpg< is a chunk of fossil coral.
Difficult to say on the others. The piece for which you provided three pictures might be petrified wood, or could also be coralline reef material. It really needs very close examination with a loupe to check whether it has a cellular structure and, if so, what kind. The final item might also be petrified wood, but the pictures are too out of focus to see any internal structure.