6.8" Tall, Red And Yellow Jasper Stand-up - Marston Ranch, Oregon
This is a colorful, polished stand-up made from jasper replaced petrified wood from Marston Ranch, Oregon. It is polished on two faces to show the detail and has been cut flat along its base for presentation. The jasper replacement left a beautiful coloration with hues of red and yellow but destroyed the detail that would allow for the type of tree to be identified.
Petrified wood is the name given to wood that has been turned into stone (fossilized) through the process of permineralization. All of the organic matter becomes replaced by minerals, while much of the original structure such as tree rings in retained. For this to happen the wood needs to be buried in an environment both low in oxygen (preventing decomposition) and with flowing, mineral-laden water. The coloration is due to the various minerals that are present during fossilization. For example red colors are due to iron compounds, greens due to copper, etc.
Marston Ranch Jasper is a colorful variety of breciatted jasper that only occurs at the Marston Ranch in Jefferson County, Oregon. Jefferson County falls within the Ash Butte, which is a geologic formation that resulted from settling of volcanic ash along its sides. This environment is perfect for both jasper and petrified wood to form. The exact origins surrounding whether or not this is indeed jasper replaced petrified wood, or a type of jasper formed by a different mechanism, is still up for debate.