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Geology/Petrified nutshell


petrified nut shell
petrified nut shell  
I found the specimen at an oil separator well near Eaton, CO in Weld County.  I also found the piece of (obviously) wood that is in the picture on the right side.  Upon re-evaluating my findings, I noticed that two of the pieces of what appears to be a petrified nutshell, fit together perfectly.  A week prior, my son had found a similar rock less than 1 mile away, and down hill (north east).  Could it be possible that this specimen is actually a nutshell, and could it have become petrified within the last couple of hundred years? Do the oil-field wells have any particular effect on the state of our current geology? I FIND PETRIFIED WOOD IN COLORADO REGULARLY! This light-colored wood is much different that the previous samples I've been collecting. Thanks for your time and expertise!

Hi there Des,
Looks like an interesting find. However, your attached picture is only thumbnail quality and I can't make out any details to give you some detailed answer. In a nutshell (no pun intended), around Eaton, CO you are in the vicinity of major outcrops of the so called Laramie Rock formation, which is Upper Cretaceous or about 66 72 million years olds. At this time a large but shallow ocean, the so called interior Cretaceous seaway, which covered most of Colorado was receding, and in Weld County gave way to large coastal plains and coastal swamps, flanking the Western Interior Seaway. Forests thrived (hence the petrified wood) and large amounts of dead plant material even formed some coal beds, which have been mined in Colorado.
Unfortunately I cannot tell you more because of the low resolution in the pictures. However, you are not terrible far from our geology department at Metropolitan State University in Denver and you are welcome to stop by and show us your artifacts in person. My colleague is much better in identifying fossils than I am. If we make an appointment we could also get you together with a Paleobotanist from the Biology faculty, who could tell you even more. Unfortunately he is retiring, this is why we need to make a specific appointment.
If you are interested in visiting us, here is my work email:
We can discuss details via email.


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Uwe Richard Kackstaetter, Ph.D. (Dr.K)


I can answer questions concerning minerals, mineralogy, gems, metals, groundwater, national and international geoscience field trips and anything that has to do with geology. As a public service and part as training for new geoscientists, our university department provides detailed FREE mineral identification for individuals with available non-destructive and destructive analytical procedures and a several page report. Please contact me for details or go to for details..


I am a professor of applied geology and mineralogy with many hours of field experience. Furthermore, I enjoy recreational gold prospecting and mineral collecting. As a professor I am engaged in research concerning minerals, their identification and their occurrence. I am currently developing inexpensive, accurate mineral identification procedures to be used by experts and lay people alike.

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