5/27/24
Time for solemn remembrance on this US Memorial Day weekend 2024 --------------------- *Newly added books 5/27/24 We continue to add books from the extensive Charles Eastman Library, each of which are quite a bargain, so check them out by clicking "The Bookshelf" link below. And here's a shout-out to a new non-profit organization devoted to fossil forests throughout the world - to the people who study them, to the people who collect their treasures, and to news about new discoveries. Please read our ringing endorsement by clicking the Friends of Fossil Forests link below. ------ Jim Mills and Beth Myers |
Welcome to Mills Geological quality identified petrified wood and plant fossils from around the globe |
Our featured specimen
Vitaceae Family wood surrounded by algae (Vitaceoxylon sp.)
Miocene, Trout Creek Formation "Green Algae Wood Site" near McDermitt, Nevada/Oregon ** An exquisite small slab -- great opportunity here! We pounce on every McDermitt green algae wood site specimen we see -- but we only get that chance occasionally. The so-called Green Algae Wood Site is just one of the many different diggings associated with the McDermitt area. But, it has long since been depleted and specimens now only come out of old collections. The green color results from a trivalent form of iron oxide that colors the silicon dioxide as a trace element -- not because the living algae was green. Why this particular oxide colored only the algae and not the wood is somewhat of a mystery but it is likely the result of the algae being softer and more porous and for some reason the trivalent iron ions were only available at the very beginning of the petrification event. Later infusions of silica were much darker as a result of bivalent iron ions and perhaps an occasional trace of manganese as well as some of the dark minerals like biotite and olivine in the ash began to weather. If your collection does not have a representative specimen from this now depleted site, consider acting on this one - it might be a long time before you get another opportunity. We have posted a photomicrograph of the anatomy of the wood. Notice that the vessels are perfectly evenly-spaced between the distinct growth rings and they are really large (between 100 and 200 microns). There is very nice definition of stromatolitic algal colonies giving good evidence that the limb was underwater, providing an anchor for algae to grow upon and meanwhile succumbing to hydrolization of much of the wood, making it a bit remarkable that any of the anatomy survived! Often in these cases we are unable to obtain a good taxonomic identification. This is a handsome specimen, which tells its own story of its taphonomy. An excellent choice for addition to a serious collector's holdings. 3.75” x 3" on the polished face; 7/16" thick slab $115 |
Pepper tree (Schinoxylon actinoporosum)
Laney Shale Member, Green River Formation, Eocene Blue Forest, Wyoming ** You already have a specimen of Schinoxylon in your collection? Not surprising! But this one is a bit different because it is a small and perfect piece. The wood itself is a complete, absolutely perfect round with all of the bark (phloem) separated from the wood (xylem) by luminous agate which is punctuated by two fine fortification patterns. While our photograph doesn’t do it justice, the agate is translucent and gorgeous. At 55 mm in diameter, this specimen falls into the "miniature" specimen category used by mineral collectors (i.e. between 30mm and 64mm in maximum size). You won't find a better representative of perfection than this one in an Eden Valley "mini" specimen. If you are interested in the taphonomy and mineralogy of petrified woods from Eden Valley, you can check out the lengthy article in the publication Geosciences that I coauthored in 2019 with George Mustoe and Mike Viney entitled “Mineralogy of Eocene Fossil Wood from the Blue Forest Locality, Southwestern Wyoming, United States.” It is open access and can be downloaded at https://www.mdpi.com/2076-3263/9/1/35 The article can explain, in detail, the complex process that resulted in perfect specimens like this one. 2.25” in diameter on polished face; 3/16" thick slab $54 |
Cherry (Prunus sp.)
Trout Creek Formation Miocene
Bretz Mine Airport Site, McDermitt Nevada/Oregon
** Ahhh ... we just love these slabs with the intricate patterns produced by ground water penetrating deep inside the petrified log in order to produce distinctive leaching patterns of contrasting tones of chocolate and tan. This specimen even has some nice preservation of the woody fine structure of the very large genus, Prunus. Take a look at our closeup photomicrograph of the woody fine anatomy. The Bretz Mine was a mercury mine in the mid-20th century and the “airport” was a gravel strip to enable executives and specialized technicians to fly into this remote part of northern Nevada and southern Oregon. These days, only rockhounds and hunters visit the area and the airport is grown over with sagebrush and other native species so it is barely visible, but the name persists as a locality reference for diggings (some of which go down 14 feet) of fine petrified wood specimens. Another interesting fact: the site is actually related to a giant volcanic caldera that was active during Miocene times (Trout Creek Formation) and which produced the mercury that was mined -- as well as the wood that is still collected.
7.5" x 6" on polished face; 9/16" thick slab $75
Trout Creek Formation Miocene
Bretz Mine Airport Site, McDermitt Nevada/Oregon
** Ahhh ... we just love these slabs with the intricate patterns produced by ground water penetrating deep inside the petrified log in order to produce distinctive leaching patterns of contrasting tones of chocolate and tan. This specimen even has some nice preservation of the woody fine structure of the very large genus, Prunus. Take a look at our closeup photomicrograph of the woody fine anatomy. The Bretz Mine was a mercury mine in the mid-20th century and the “airport” was a gravel strip to enable executives and specialized technicians to fly into this remote part of northern Nevada and southern Oregon. These days, only rockhounds and hunters visit the area and the airport is grown over with sagebrush and other native species so it is barely visible, but the name persists as a locality reference for diggings (some of which go down 14 feet) of fine petrified wood specimens. Another interesting fact: the site is actually related to a giant volcanic caldera that was active during Miocene times (Trout Creek Formation) and which produced the mercury that was mined -- as well as the wood that is still collected.
7.5" x 6" on polished face; 9/16" thick slab $75
Palm trunk (Palmoxylon sp.)
Catahoula Formation Oligocene
near Rockland, Tyler County, Texas
** Very nice palm specimen with excellent pattern in tan and black from the Catahoula Formation in Texas. Invasion by ground water after petrification turns out to be a treat for the petrified wood collector because it has imparted a really interesting pattern to the polished slab, providing great contrast and beauty as it lightened the periphery and the heart of the trunk. A terrific slab of palm trunk!
10” x 7” on the polished face; 3/4" thick slab $110
Catahoula Formation Oligocene
near Rockland, Tyler County, Texas
** Very nice palm specimen with excellent pattern in tan and black from the Catahoula Formation in Texas. Invasion by ground water after petrification turns out to be a treat for the petrified wood collector because it has imparted a really interesting pattern to the polished slab, providing great contrast and beauty as it lightened the periphery and the heart of the trunk. A terrific slab of palm trunk!
10” x 7” on the polished face; 3/4" thick slab $110
Black Locust encased in algae (Robinia zirkelii)
Miocene, Trout Creek Formation
Diggings near McDermitt, Nevada/Oregon border
** McDermitt has produced fossil wood in algae from three different sites where the specimens have been preserved in three distinct colors - a different color of the fossil algae at each site. We suspect the differences are the result of different volcanic events over the span of Trout Creek time. All of the geological evidence points to there being numerous eruptions separated by longer periods of quiescence in between eruptions. Color differences are most likely caused by complex differences of the geochemistry of the ash along with different chemical characteristics of the groundwater which began to weather the volcanic ash to provide the silica for permineralization. The result - brown, yellow and green coloration in the fossil algae. This specimen is from the brown algae site - the one with the best preservation of the stromatolitic algae colonies but with wood preservation nearly approaching unidentifiable. The algae appear to have had more time to form and grow at the brown algae site giving the fungal and bacterial agents more time to attack and destroy wood tissue. Hydrolization by the water also added to the disintegration of the wood tissue. Fortunately, there is just enough remaining anatomy preserved to get a good identification on this particular stem. It is a Black Locust. The Latin name Robinia zirkelii is applied to all fossil Robinia in North America. The color changes reflect the differences between iron oxides with different valences of the iron ion in the compound. We love having all three sites represented in our own collection so they can be displayed beside one another to help illustrate the story of volcanic activity during Trout Creek time. We have reason to believe that all three sites are now completely depleted so this is a rare opportunity to add a brown algae site slab to your collection if it is currently missing.
5.75” x 4.25” on polished face; end cut varies from 3/8” to 1.5” thick $80
Miocene, Trout Creek Formation
Diggings near McDermitt, Nevada/Oregon border
** McDermitt has produced fossil wood in algae from three different sites where the specimens have been preserved in three distinct colors - a different color of the fossil algae at each site. We suspect the differences are the result of different volcanic events over the span of Trout Creek time. All of the geological evidence points to there being numerous eruptions separated by longer periods of quiescence in between eruptions. Color differences are most likely caused by complex differences of the geochemistry of the ash along with different chemical characteristics of the groundwater which began to weather the volcanic ash to provide the silica for permineralization. The result - brown, yellow and green coloration in the fossil algae. This specimen is from the brown algae site - the one with the best preservation of the stromatolitic algae colonies but with wood preservation nearly approaching unidentifiable. The algae appear to have had more time to form and grow at the brown algae site giving the fungal and bacterial agents more time to attack and destroy wood tissue. Hydrolization by the water also added to the disintegration of the wood tissue. Fortunately, there is just enough remaining anatomy preserved to get a good identification on this particular stem. It is a Black Locust. The Latin name Robinia zirkelii is applied to all fossil Robinia in North America. The color changes reflect the differences between iron oxides with different valences of the iron ion in the compound. We love having all three sites represented in our own collection so they can be displayed beside one another to help illustrate the story of volcanic activity during Trout Creek time. We have reason to believe that all three sites are now completely depleted so this is a rare opportunity to add a brown algae site slab to your collection if it is currently missing.
5.75” x 4.25” on polished face; end cut varies from 3/8” to 1.5” thick $80
"Haw" or "Linden" tree (Viburnum sp.)
Mehama Volcanics Unit, Little Butte Formation, Oligocene Sweet Home area, Oregon ** Trees and shrubs of this genus in North America are called by the common name "Haw," while those in Europe are called "Linden." Call it what you want according to your own location! While much of the Sweet Home wood's preservation of anatomy can be hard to find, this one does have visible structure throughout the slab along with those well-defined annual growth rings. The first thing that you should notice is the angular character of most vessels. And note the vessels are almost entirely singular and their density is well within the range of 40 to 100 per square millimeter. 5.5" x 4" on polished face; 5/16" thick slab $48 |
Schilderia
Chinle Formation, Triassic
old Paulsell Ranch, Navajo/Apache Counties, Arizona
** The striking feature of this nice Schilderia is the definition of the radial grain, which is a distinguishing feature of Triassic Schilderia. The genus Schilderia is a very scarce fossil wood in the Chinle Formation, accounting for less than 2% of the total amount of wood from the region. Its taxonomy has been an enigma over the years but most paleobotanists now agree that it should be assigned to the Family of Gnetales. Oddly, one of the only living members of this family in the Southwest region these days is a desert shrub in the genus Ephedra which is usually referred to by its common name of “Mormon Tea.” It has been found in different small deposits of the region but always as a minor constituent of the deposit accompanying the more common Araucarioxylon and Woodworthia. This is a handsome example of an unusual Chinle genus. The 60,000 acre Paulsell Ranch was adjacent to the east boundary of Petrified Forest National Park and acquisition of the ranch by the Park Service was authorized in 2004. Specimens from the old Paulsell Ranch are now no longer available for collecting so if your collection is enhanced by rare species from closed localities - this is a great addition.
6” x 4.5" on polished face; end cut varies in thickness from 1.75” to 1” $58
Chinle Formation, Triassic
old Paulsell Ranch, Navajo/Apache Counties, Arizona
** The striking feature of this nice Schilderia is the definition of the radial grain, which is a distinguishing feature of Triassic Schilderia. The genus Schilderia is a very scarce fossil wood in the Chinle Formation, accounting for less than 2% of the total amount of wood from the region. Its taxonomy has been an enigma over the years but most paleobotanists now agree that it should be assigned to the Family of Gnetales. Oddly, one of the only living members of this family in the Southwest region these days is a desert shrub in the genus Ephedra which is usually referred to by its common name of “Mormon Tea.” It has been found in different small deposits of the region but always as a minor constituent of the deposit accompanying the more common Araucarioxylon and Woodworthia. This is a handsome example of an unusual Chinle genus. The 60,000 acre Paulsell Ranch was adjacent to the east boundary of Petrified Forest National Park and acquisition of the ranch by the Park Service was authorized in 2004. Specimens from the old Paulsell Ranch are now no longer available for collecting so if your collection is enhanced by rare species from closed localities - this is a great addition.
6” x 4.5" on polished face; end cut varies in thickness from 1.75” to 1” $58