How is petrified wood formed?
This past weekend I went out searching for some petrified wood. I really enjoy finding things... petrified wood, mushrooms, gems, Easter eggs... I just like the hide-and-seek games I guess. I didn't find as many pieces as I usually do, but I lucked across a really big piece that was mostly buried, so that was fun! And there was this one piece that was so light in color and in weight that I actually touched it against my teeth to make sure it was petrified wood instead of just regular wood. Which, naturally, lead me to thinking, what exactly is petrified wood? How is petrified wood formed?
Well, petrified wood is a fossil. Sometimes hundreds of millions of years old. It is formed when plant material, such as a tree, is buried in sediment and protected from decay by oxygen and organisms. Then, groundwater rich in dissolved solids passed through the sediment and replaces the plant matter with inorganic matter such as silica, calcite, pyrite, quartz, and even opal. Meaning, there's all sorts of colors and mineral make-ups of petrified wood. Desertusa.com gives us the following chart for minerals and which colors they can create when forming petrified wood:
Copper - green/blue Cobalt - green/blue Chromium - green/blue Manganese - pink Carbon - black Iron Oxides - red, brown, yellow Manganese Oxides - black Silica - white, grey
Some petrified wood can be exact replicas of their previous form, but near-perfect specimens are rare, and recognizable bark and wood grain are common. There's actually an Entire petrified forest in Arizona, made up almost entirely of quartz. Each piece is basically a giant crystal. That would be incredible to see... sun coming up and all of a sudden there's a field of giant glittering crystals shimmering in the sunlight... Next stop, Arizona!
Have you had any luck finding petrified wood?