By Abe V Rotor
Petrified wood (Pietro, rock) is a fossil formed by the infiltration of minerals into cavities between and within cells of natural wood, usually by silica (silicon dioxide, SiO2) or calcite (calcium carbonate, CaCO3). Petrification is a very slow anaerobic process.
The replacement of organic tissue by mineral deposits is so precise that the internal structure as well as the external shape is faithfully represented; sometimes even the cell structure may be determined.
Petrified rocks are cut and polished into many items of commerce and art such as furniture, adornments, and decors.~