When a volcano erupts it sends rock debris and lava down the mountains. This debris mixes with streams and water from melting snow and makes a chaotic mixture of mud, sand, gravel, and anything else in its way. These volcanic soups called lahars choke streams and mix with layers of sandstone. Over time, new water carries the mud away and leaves gravel deposits filled with sediments containing volcanic ash. Centuries later, downed trees are periodically buried by this sediment. The tubes that usually move water to the trees’ leaves and needles fills instead with silica dissolved from the ash into the groundwater. The silica slowly replaces cell walls and crystallizes as chalcedony, or quartz, a process that takes about 100 years.
In the famous petrified forest of Arizona, the ground water was also full of iron, which combined with quartz to create the brilliant rainbow of colors seen in the fossil wood there. Petrified wood is usually formed in downed trees, but in Yellowstone National Park, entire fossil forests remain standing, victims of raging lahars that calcified them in place. Varieties of petrified wood can be found with agates, opals, and other minerals and in crazy patterns formed by insects and even clams, as is the case with the rare Australian, “peanut wood.”
Because the stone comes from ancient trees, it is said to embody the wisdom and patience of the ages. It is considered a powerful stone for Earth healers who use it to deepen one’s connection to nature. It is also used by those who want to turn past weaknesses into new growths, much the same way that the perishable wood became immortal stone. Petrified wood is said to strengthen the gallbladder and liver, make one feel ageless, and bolster one’s commitment to a long-term relationship. The stone of business success, it can help to stabilize one’s environment and emotions so that the best decisions can be made.