last update   5/25/17

Welcome to

Mills Geological

High-quality, identified petrified wood and plant fossils from around the globe


Our Featured Specimen






Thanks for patronizing Mills Geological!





Beth and Jim

Jim@millsgeological.com



Laurel (Umbellularia sp.)

Santa Barbara Canyon, near New Cuyama, California

** Location, location, location.  This sweet slab of laurel not only has terrific patterning and beautiful chocolate coloration, it is from a highly unusual locality.  Wood from this area is rarely found on the market.  New Cuyama comes from the Chumash Indian name for "clams," and is located in far northeastern Santa Barbara County, California.  Well named because indeed the area contains considerable deposits of fossil clams in marine strata which interfinger with terrestrial deposits with only occasionally finds of petrified wood.  These interfingering deposits are ancient seashore environments which changed back and forth from marine to terrestrial as sea levels changed and tectonic forces started pushing up land mass at the point where the Pacific Plate is being subducted under the North American Plate.  This nice laurel is the ancient ancestor of present day Umbellularia californica trees which occupy coastal habitats.  They go by the common name of “Bay Laurel” and are the source of the bay leaves used in cooking.  Interesting geology, interesting fossils, interesting etymology all wrapped up in a single specimen of handsome petrified wood.

6” x 5” diameter on polished face; slab varying from 1/8” to 1/4” in thickness  $89

Pepper tree (Schinoxylon actinoporosum)

Laney Shale Member, Green River Formation, Eocene

Blue Forest, Wyoming

** In spite of what you may see in many descriptions of petrified wood, bark is not all that commonly preserved.  Well, on the cut face on this specimen, it is the only thing one sees! So, how do we know it is a pepper tree?  Just turn the end cut upside down and there is plenty of wood preserved to make the determination.  The lapidary chose to make the bark the feature on this specimen simply because it is so unusual (not to mention aesthetic with all of the bark beginning to disassemble into short strips).  In this choice piece, over 95% of the entire bark periphery is present.  The quartz druse-lined cavity in the middle of the cast adds even more aesthetic interest to the specimen.  So, as one can easily see, this is a unique specimen from the ever-surprising Blue Forest.  It will make an impressive addition to even the most advanced collector’s trove of specimens.

4” x 2.5” on polished face; 2.5” thick end cut   $39


Palm    (Palmoxylon sp.)

Catahoula Formation; Oligocene

Lake Sam Rayburn, Texas

** This is a NICE slice of palm with good preservation of ground mass as well as vascular bundles.  The Lake Sam Rayburn area has been a popular collecting site for Texas rockhounds for many years, and this slab is a good example of why they like the area.  Many of us are not lucky enough to hunt there or find there!  The locality consistently produces attractive specimens.   Be sure to look at our photomicrograph of this specimen.

6 x 4 inches on polished face; 1/2” thick slab    $55

Palmoxylon

Bridger Formation, Eocene

Big Sandy Reservoir, Wyoming

** Here's a remarkably well-preserved palm trunk with an attached frond base from the Big Sandy Reservoir classic locality near Farson, Wyoming.  The crescent shaped structure at the 12:00 o’clock position on this slab is the base of a frond as it leaves the trunk.  We see a lot of great palm trunks from the Big Sandy diggings but they only seldom have one of these frond bases included on the specimen.  This specimen has the added feature of showing how susceptible palms are to heart rot.  The white agate in the center of the slab has filled a cavity that was the result of heart rot.  Since monocots such as palms lack medullary rays, they do not have the same ability as dicot species of plants to protect their hearts with toxins to kill off bacteria and fungus growth.  By contrast, dicots are able to develop compounds such as turpines (from which we make turpentine) in the cambial layer and strategically place these toxic chemicals into the trunk of the tree to combat fungus growth. Fascinating slice.

7" x 6.25” on polished face; 1/2" thick slab  $119


Primitive Conifer   (Araucarioxylon arizonicum)

Chinle Formation, Triassic

Milky Ranch, southeast of Petrified Forest National Park, Arizona

** BLUE!  What a fantastic background color in this Arizona piece!  The annual growth rings highlighted in dark gray hues make this piece from the Old Milky Ranch a true standout.   There are so many colorful variations of Arizona’s famous rainbow wood that there is always room for one more in any collection!  If you strive for aesthetics AND obvious growth rings in your petrified wood collection, this is a fine candidate to consider.

10” x 6” on polished face; 5/8” thick slab    $129

Alangium sp.

Claiborne Group, Yegua Formation, Middle Eocene

near Crockett, Houston County, Texas

** This genus does not have a common name in English of which we are aware.  The Eocene in Texas’ wide coastal plain has produced many genera that are now restricted to tropical latitude climates.  Alangium is one of them, and is often not represented in the collections of even the most advanced petrified wood collectors.  We have been lucky enough in the past to have a few of this genus in our inventory, but this is the first time we have seen wood from Crockett.  This specimen has some really excellent preservation of woody fine structure – see our photomicrograph to the right. It is likely that our Texas friends will all have some of this material in their own collections, so we are happy they decided to share with the rest of us!  This will be a wonderful addition to the collection of an avid petrified wood species and/or locality collector.

8.5” x 6.5” on polished face, 3/8” thick slab   $159

Palm   (Palmoxylon sp.)

Miocene

Hanidh, Eastern Province, Saudi Arabia

** Great opportunity here!  This log was found and brought home by an American Geologist working in the Saudi Arabian oil fields in the last half of the 20th century.  It is a locality almost guaranteed to be unrepresented in most American collections!  If that includes you, then here’s an opportunity to fill that vacancy.

7.5 x 2.25 inches on polished face; 3/8” thick slab    $75

Fossil Wood in Algae

Trout Creek Formation, Miocene

Malheur County, Oregon (northwest of McDermitt, Nevada)

** Interesting piece! One very good-sized limb section is surrounded by fossil stromatolitic algae.  The wood was under water for a considerable period of time as evidenced by the very large amount of stromatolitic algae anchored to it.  Thus, while the wood does not have excellent preservation of fine structure because the water would have been hydrolyzing it over time, it is clearly recognizable as wood.  Notice that the wood has a second center of the branch sweeping out to the one o’clock position.

7" x 5" on polished face; 3/8" thick slab    $79



SOLD