Mystery Object

The mystery object is

PETRIFIED WOOD

from Arizona.

Petrified wood is a special type of fossil. It has the tree’s original shape and structure, but the living material has been replaced by minerals and stone.

Our specimen began forming millions of years ago when logs washed into an ancient river or sea. The logs were buried by great amounts ofsediment, but because there was very little oxygen, the logs did not decay normally.

The log broke down very slowly over hundreds of years. Minerals absorbed into the wood. The minerals replaced pieces of the wood as it decayed.

Our particular specimen is sometimes called “rainbow” petrified wood because of its many colors. It is made of almost solid quartz. Quartz is usually clear, but when elements are in the water/mud during the petrification, other colors are produced.

Here is a list of elements and the colors they may produce in the petrified wood:•carbon - black•cobalt - green/blue•chromium - green/blue•copper - green/blue•iron oxides - red, brown, and yellow•manganese - pink/orange•manganese oxides - black/yellow

Petrified Forest National Park in the Painted Desert of Arizona contains one of the world’s largest and most colorful areas of petrified wood.