Petrified wood is a type of fossil. It comes from the Greek word petro meaning “rock” or “stone,” and literally means “wood turned to stone.”
Imagine a forest of long ago: A tree falls down and is later washed into a nearby water source, such as a river or a lake. The wood becomes saturated with water and is later buried by mud, silt, or ash. Over time, the minerals from the water react with the wood. This begins the petrifaction process, which can occur in one of three ways:
1. Permineralization - minerals fill in the voids left in the sediment by the decaying wood
2. Recrystallization - the basic composition of the wood remains the same, but, new crystal structures form in its place
3. Replacement - the original organic material is replaced by inorganic minerals
The petrification process can preserve many of the wood's original details. Tree rings, wood grain, and even the original cell structure can sometimes be seen in petrified wood.
The Beauty of Petrified Wood
During the petrifaction process, organic material is most often replaced by quartz. In its purest form, quartz is a colorless mineral. When other elements are present in the water or sediment during petrifaction, they can influence the color of the quartz. This gives petrified wood its stunning pallet.
• Red, Orange, Yellow, Brown - Iron Oxide
• Green - Iron Oxide or Uranium
• Blue - Copper, Manganese, Cobalt, or Chromium
• Violet, Purple - Iron Oxide or Manganese
• Black - Iron Oxide, Manganese, or Carbon
• White, Gray - Silicon dioxide
Quartz is a hard and brittle mineral that fractures easily under stress. Its crystalline nature does not create clean breaks at even intervals. This is why petrified wood breaks like a glass rod when stressed. This gives it the appearance of a series of logs evenly cut by a chainsaw.