Elements such as manganese, iron, and copper in the water/mud during the petrification process give petrified wood a variety of color ranges. Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on a yellow, red, or other tint.
Following is a list of contaminating elements and related color hues: carbon – black; cobalt – green/blue; chromium – green/blue; copper – green/blue; iron oxides – red, brown, and yellow; manganese – pink/orange; manganese oxides – blackish/yellow.
Petrified wood can preserve the original structure of the stem in all its detail, down to the microscopic level. Structures such as tree rings and the various tissues are often observed features.
Petrified wood is a fossil in which the organic remains have been replaced by minerals in the slow process of being replaced with stone. This petrification process generally results in a Quartz Chalcedony mineralization. Special rare conditions must be met in order for the fallen stem to be transformed into Fossil Wood or Petrified Wood. In general, the fallen plants get buried in an environment free of oxygen (anaerobic environment), which preserves the original plant structure and general appearance. The other conditions include a regular access to mineral rich water flowing through the tissues, replacing the organic plant structure with inorganic stone. The end result is petrified wood, a plant, with its original basic structure in place, replaced by stone. This process could occur in less than one thousand years. Exotic minerals allow the rare red and green hues that can be seen in more rare specimens.