Like animal fossils, petrified wood is an extremely cool relic of Earth’s ancient past. However, while both are technically fossilized remains, the two are actually quite different. To understand exactly why this is, let’s take a look at how this unique type of fossilized wood is made.
Petrified Wood Formation
Like other types of fossils, petrified wood forms underground over thousands of years. However, many fossils are simply imprints of an animal left in sediment or ash, whereas fossilized wood forms when the organic material in the tree or vegetation is replaced by stone over time.
Typically, the process begins when a tree is buried underneath ash or sediment, which preserves it and prevents decay from the lack of oxygen. Over time, water flowing through the sediment and into the wood leaves behind mineral deposits in the plant’s cells.
Eventually, the organic materials within the cells start to decay, leaving the mineral deposits to replace the organic material. This results in the piece of wood turning completely to stone while still keeping the original structure of the cell tissue. This allows you to see the tree rings and individual cells if you look with a microscope.
Typically, the organic material is replaced by a silicate material such as quartz. This leaves behind a clear or white colored stone. However, a wide range of different colors can also occur when other minerals are mixed in with the silicate. For instance, copper generally results in a green or bluish color. On the other hand, iron can create shades of yellow, red, and brown.
Where to Find Petrified Wood
There are a number of different petrified forests located all over the globe, although the United States is home to far more than most countries, including the Petrified Forest National Park. The majority of American petrified forests are located in the western part of the country, with the exception of the Mississippi Petrified Forest and the Gilboa Fossil Forest in New York.
South Dakota, North Dakota, Arizona, Colorado, Wyoming, and Utah are all home to fantastic petrified forests. Mississippi, Washington, and Oregon are, as well. Petrified wood can also be found in numerous places in South America, Europe, Australia, India, and China, among others. In most cases, the wood found in each location has its own unique characteristics due to variations in tree species, soil conditions, climate, and other environmental factors. This compels collectors to travel all across the globe in search of unique pieces.
Combine a petrified wood search with rockhounding for a fun day of digging up the geological past. See if there’s an area you can explore in your neck of the woods. Or, make it a part of your next vacation!
Featured Image from Noel DeJesus/Unsplash
