Araucarioxylon
arizonicum
Division
Pinophyta (conifers), Class Pinopsida, Order Pinales, Family Araucariaceae
Geological
Time: Late
Triassic, Norian-Carnian Stage
Size: Fossil
is 75 mm long by 65 mm wide by up to 34 mm thick; weight 199 grams.
Fossil Site:
Winslow, Arizona
Code: PW32
Price: Sold
Description:
This specimen of highly-colored petrified wood from the Chinle Formation
(Norian-Carnian Stage, ~225 million years old) deposits of Winslow,
Arizona comes with a story. Almost 25 years ago, I came across a few
examples of this rare material at a rock shop in southern Utah. I
purchased a sample and thought little of it. After my return home,
I decided to try to obtain some
larger specimens. I had been unsuccessful until a few years ago. The
rich green color is the result of ~2% Chromium content. While the
many types of petrified wood come in a panoply of colors, only a very
few types are green; the only other known to me is found in Africa.
This material comes from a small deposit near Winslow and is not known
from any other location. Araucarioxylon arizonicum is the state fossil
of Arizona, and is the taxon comprising some 90% of all specimens
found in the Petrified Forest National Monument. It was a coniferous
tree standing some 150-200 feet tall, and some 6-8 feet in diameter.
Its closest relatives today are the Monkey Puzzle Tree of South America
and the Norfolk Island Pine. All my initial specimens are now gone;
I was able to acquire a few more this year, but have been told no
more will be available from the field, as it appears to be played
out. This one has a flattened base and has received a high polish
on the display side, making it an excellent specimen for a cabinet
collection or to serve as an interesting paperweight as a conversation
starter in the office. |
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