What replaces the wood of a once living tree to form petrifiedwood?

Petrified wood forms when the organic materials of a once-living tree are replaced by minerals, primarily silica, over millions of years. This process, known as permineralization, occurs when water rich in minerals seeps into the tree’s tissues, gradually replacing the cellulose and lignin with minerals while preserving the original structure. As a result, the tree retains its shape and appearance but becomes a fossilized form of wood made primarily of stone.