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September 12, 2026
We'll be going on our fall hiatus in two weeks, but before then, we will be listing more fantastic specimens that we discovered this summer. Jim recently acquired another old collection and it has some handsome and fascinating pieces. So some new ones one from that collection today. Thank you, as always! Beth and Jim ------ |
Welcome to Mills Geological quality identified petrified wood and plant fossils from around the globe |
Our Featured Specimen
Ancient conifer (Gymnosperm)
Morrison Formation (Late Jurassic)
Hanksville area, Utah
** This log was well along towards becoming just vegetative debris on the forest floor when a volcanic event luckily saved it just in time for future petrified wood collectors. That history should tell you that the structure of this slab is not of the perfection that would send a paleobotanist right to the computer keyboard to write an article. Instead, it would be of more interest to those collectors who value the patterns created by bacterial and fungal activity after the tree is dead and down. Fortunately, those bacteria and fungus were stopped dead in their tracks just in the nick of time when buried by volcanic ash in the Late Jurassic. No oxygen meant no more destruction and soon, groundwater carrying silicic compounds along with traces of iron oxides began the process of permineralization. Those bands of fortification agate near the periphery are the result of desiccation and shrinkage cavities being the first areas to receive precipitation of silica - well prior to that silica also included mostly iron and manganese chromophores to darken the silicification of the wood. The luck of the lapidary even exposed a small cool spike knot coming out of the limb at the 2 o'clock position. This specimen came out of an old collection and the previous collector thoughtfully penned the place and date on the reverse side to give positive assurance of the provenance for this wonderful specimen. This one tells its own colorful petrification story and collecting history.
5" diameter on polished face; 3/4" thick end cut $65
Morrison Formation (Late Jurassic)
Hanksville area, Utah
** This log was well along towards becoming just vegetative debris on the forest floor when a volcanic event luckily saved it just in time for future petrified wood collectors. That history should tell you that the structure of this slab is not of the perfection that would send a paleobotanist right to the computer keyboard to write an article. Instead, it would be of more interest to those collectors who value the patterns created by bacterial and fungal activity after the tree is dead and down. Fortunately, those bacteria and fungus were stopped dead in their tracks just in the nick of time when buried by volcanic ash in the Late Jurassic. No oxygen meant no more destruction and soon, groundwater carrying silicic compounds along with traces of iron oxides began the process of permineralization. Those bands of fortification agate near the periphery are the result of desiccation and shrinkage cavities being the first areas to receive precipitation of silica - well prior to that silica also included mostly iron and manganese chromophores to darken the silicification of the wood. The luck of the lapidary even exposed a small cool spike knot coming out of the limb at the 2 o'clock position. This specimen came out of an old collection and the previous collector thoughtfully penned the place and date on the reverse side to give positive assurance of the provenance for this wonderful specimen. This one tells its own colorful petrification story and collecting history.
5" diameter on polished face; 3/4" thick end cut $65
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Conifer (Pinales order)
Ash of Juniper Mountain Volcanic Center; Miocene Coal Mine Basin, South of Marsing Idaho ** You won't find many of these Idaho specimens, particularly full round specimens, on the market any more. The best of the Coal Mine Basin deposit was depleted long ago and now it is only old collections that yield the intriguing limbs from this area about 30 miles south of Marsing, Idaho. If you value interesting patterns in your specimens and don't have the Coal Mine Basin area represented - jump on this one - it has really well-preserved tracheids in the wood anatomy and a most unusual polished-face pattern. Don't be fooled by our photomicrograph - we really zoomed in to show the tracheids but they are barely visible with a 10X loupe. The Juniper Mountain Volcanic center produced many surrounding ash layers - some of which contain petrified wood and some are completely barren. The Coal Mine Basin was perhaps the most prolific producer but even at that, the amount was quite limited. This beauty comes out of an old collection. 2.25" x 2" on the polished face; end cut varies from 2" to 2" thick $45 |
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Vesselless dicotyledon (Angiosperm) Trout Creek Formation, Miocene Zimmerman Ranch at the McDermitt diggings, Oregon/Nevada ** Spectacular root section of this fascinating material. Look at the closeup photo and note that while there are no vessels, the medullary rays are quite wide, much too wide to be any kind of conifer. There are five families of modern angiosperm trees that have no vessels. Those families are Trochodendraceae, Winteraceae, Tetracentraceae, Amborellaceae and Chloranthaceae. All of these families are extremely primitive and there may have been additional Angiosperm families early on but now extinct that also were vessselless. Additionally, most of the families have only a single genus and many have only a single species in that genus. All of them depended on tracheids to transport water, the same strategy used by Gymnosperms. The specimen we feature here is a root section with various dimples of rootlets and smaller roots protruding in different directions at different angles. As is typical of roots, the emanating rootlets take the easiest path available - they do not favor directions where sunlight is the most prominent controlling factor as it is for limbs and branches. If your objectives with fossil wood include scarcity, unusual anatomy with an emphasis on growth ring and ray presentation as part of picture-perfect patterning - you may have just found the next addition to your collection. 3.75" x 2" on polished face; 4.25" long root section $75 |
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