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Silicified wood preserved in the Güdül fossil forest site in the Galatian Volcanic Province (GVP) near Ankara in Central Anatolia is described. The material comprises six petrified wood samples that date from early to middle Miocene. The woods have very low rays (2–5 cells high), bordered tracheidal pitting (9–10 μm), pinoid cross-field pits and very thin, unpitted, smooth walls of axial parenchyma and rays. This combination of characters indicates affinity to the fossil-genus Glyptostroboxylon. The presence of this wood genus suggests that the local environment was either riparian or wetland forest.

Measuring density of silicified wood and determining weight loss after 450°C heating provides useful data for interpreting the process of permineralization. These simple gravimetric methods do not replace X-ray diffraction, electron microscopy, polarized light microscopy, Raman spectroscopy, and other specialized techniques for studying fossil wood, but they can be performed rapidly, and require minimal laboratory facilities. Woods mineralized with opal have densities of 1.9–2.1 g/cm3, compared to 2.3–2.6 g/cm3 for wood mineralized with chalcedony or quartz. Weight loss after 450°C heating, commonly described as “loss on ignition” can be used to roughly estimate the % of original organic matter that remains in chalcedony or quartz-mineralized wood, using the density of extant taxa for comparison. For opalized wood, 450°C weight loss mostly represents dehydration of the hydrous silica. Data from specimens from 20 localities reveal two characteristics: 1) silicified woods typically consist either of opal or chalcedony/quartz, not an intermediate mixture of the two silica polymorphs; 2) the percentage of organic matter that remains after petrifaction is usually very small.

Fascination with petrified wood has stimulated interest in understanding the process of natural petrifaction. Early attempts of modeling natural petrifaction in the laboratory have been limited to mimicking incipient permineralization resulting in the creation of silica casts of pore spaces and inner cell walls. Silica lithomorphs produced through artificial silicification provided a possible avenue for studying microstructure of wood. More recently artificial petrifaction is motivated by the goal of creating advanced ceramic materials for engineering applications. The concept of using wood as a biotemplate has led to the creation of porous ceramics by cell wall replacement. To some extent artificial and natural petrifaction processes are comparable; although, some of the materials and procedures used in the laboratory are not found in nature. Research focused on the composition and structure of fossil wood from different-aged deposits is compared with research focused on the development of wood-templated porous ceramics. Differences and similarities in the pathways of natural silicification and creation of biomorphous ceramics are discussed. The comparison between artificial and natural silicification highlights the particular significance of the degree to which (de)lignification is needed for silica permeation.

A silicified wood, Welkoetoxylon multiseriatum, gen. et sp. nov., is described from the late Early Eocene Green River Formation of southwestern Wyoming. The combination of features observed in W. multiseriatum, including latex tubes (laticifers) in the rays and abundant sheath cells, indicates affinities with the Moraceae. This is the first report of fossil moraceous wood from the Eocene of the western interior of the U.S.A. and it provides reliable evidence for the Paleogene occurrence of Moraceae in this region. The indistinct growth rings of this fossil indicate this tree did not experience a distinct dormant season.

Two fossil wood species Celastrinoxylon celastroides and Ficoxylon cretaceum are reported and described for the first time from the Farafra Oasis in Egypt. They are compared to earlier descriptions of these species from Egypt and other parts of Africa.