In geology, petrifaction or petrification is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood typifies this process, but all organisms, from bacteria to vertebrates, can become petrified (although harder, more durable matter such as bone, beaks, and shells survive the process better than softer remains such as muscle tissue, feathers, or skin). Petrifaction takes place through a combination of two similar processes: permineralization and replacement. These processes create replicas of the original specimen that are similar down to the microscopic level.[1]

Petrified wood closeup 2
Tree remains that have undergone petrifaction, at Petrified Forest National Park



One of the processes involved in petrifaction is permineralization. The fossils created through this process tend to contain a large amount of the original material of the specimen. This process occurs when groundwater containing dissolved minerals (most commonly quartz, calcite, pyrite, siderite (iron carbonate), and apatite (calcium phosphate) ),[2] fills pore spaces and cavities of specimens, particularly bone, shell or wood.[3] The pores of the organisms' tissues are filled when these minerals precipitate out of the water. Two common types of permineralization are silicification and pyritization.


Silicification is the process in which organic matter becomes saturated with silica. A common source of silica is volcanic material. Studies have shown that in this process, most of the original organic matter is destroyed.[4][5] Silicification most often occurs in two environments-either the specimen is buried in sediments of deltas and floodplains or organisms are buried in volcanic ash. Water must be present for silicification to occur because it reduces the amount of oxygen present and therefore reduces the deterioration of the organism by fungi, maintains organism shape, and allows for the transportation and deposition of silica. The process begins when a specimen is permeated with an aqueous silica solution. The cell walls of the specimen are progressively dissolved and silica is deposited into the empty spaces. In wood samples, as the process proceeds, cellulose and lignin, two components of wood, are degraded and replaced with silica. The specimen is transformed to stone (a process called lithification) as water is lost. For silicification to occur, the geothermic conditions must include a neutral to slightly acidic pH[6] and a temperature and pressure similar to shallow-depth sedimentary environments. Under ideal natural conditions, silicification can occur at rates approaching those seen in artificial petrification.[7]


Pyritization is a process similar to silicification, but instead involves the deposition of iron and sulfur in the pores and cavities of an organism. Pyritization can result in both solid fossils as well as preserved soft tissues. In marine environments, pyritization occurs when organisms are buried in sediments containing a high concentration of iron sulfides. Organisms release sulfide, which reacts with dissolved iron in the surrounding water, when they decay. This reaction between iron and sulfides forms pyrite (FeS2). Carbonate shell material of the organism is then replaced with pyrite due to a higher concentration of pyrite and a lower concentration of carbonate in the surrounding water. Pyritization occurs to a lesser extent in plants in clay environments.[3]


Replacement, the second process involved in petrifaction, occurs when water containing dissolved minerals dissolves the original solid material of an organism, which is then replaced by minerals. This can take place extremely slowly, replicating the microscopic structure of the organism. The slower the rate of the process, the better defined the microscopic structure will be. The minerals commonly involved in replacement are calcite, silica, pyrite, and hematite.[3] It is rare to find organisms preserved by replacement alone (as opposed to in combination with permineralization), but these fossils present significant importance to paleontologists because these fossils tend to be very detailed.[8]


Not only are the fossils produced through the process of petrifaction used for paleontological study, but they have also been used as both decorative and informative pieces. Petrified wood is used in several ways. Slabs of petrified wood can be crafted into tabletops, or the slabs themselves are sometimes displayed in a decorative fashion. Also, larger pieces of the wood have been carved into sinks and basins. Other large pieces can also be crafted into chairs and stools. Petrified wood and other petrified organisms have also been used in jewelry, sculpture, clock-making, ashtrays and fruit bowls, and landscape and garden decorations.


Petrified wood has also been used in construction. The Petrified Wood Gas Station,[9] located on Main St Lamar, Colorado, was built in 1932 and consists of walls and floors constructed from pieces of petrified wood. The structure, built by W.G. Brown, has since been converted to office space and a used car dealership.[10] Glen Rose, Texas provides even more examples of the use of fossilized wood in architecture. Beginning in the 1920s, the farmers of Somervell County, Texas began uncovering petrified trees. Local craftsmen and masons then built over 65 structures from this petrified wood, 45 of which were still standing as of June 2009. These structures include gas stations, flowerbeds, cottages, restaurants, fountains and gateposts.[11] Glen Rose, Texas is also noted for Dinosaur Valley State Park and the Glen Rose Formation, where fossilized dinosaur footprints from the Cretaceous period can be viewed.[12] Another example of the use of petrified wood in construction is the Agate House Pueblo in the Petrified Forest National Park in Arizona. Built by ancestral Pueblo people about 990 years ago, this eight-room building was constructed almost entirely out of petrified wood and is believed to have served as either a family home or ceremonial center.[13]

Artificial petrifaction

In 2005 scientists at the Pacific Northwest National Laboratory (PNNL) reported that they had successfully petrified wood samples artificially. Unlike natural petrification, though, they infiltrated samples in acidic solutions, diffused them internally with titanium and carbon and fired them in a high-temperature oven (circa 1400 °C) in an inert atmosphere to yield a man-made ceramic matrix composite of titanium carbide and silicon carbide still showing the initial structure of wood. Future uses would see these artificially petrified wood-ceramic materials eventually replace metal-based superalloys (which are coated with ultrahard ceramics) in the tool industry. Other vegetal matter could be treated in a similar process and yield abrasive powders.[14] Scientists attempted to artificially petrify organisms as early as the 18th century, when Girolamo Segato claimed to have supposedly "petrified" human remains. His methods were lost, but the bulk of his "pieces" are on display at the Museum of the Department of Anatomy in Florence, Italy.[15] More recent attempts have been both successful and documented, but should be considered as semi-petrifaction or incomplete petrifaction or at least as producing some novel type of wood composite, as the wood material remains to a certain degree; the constituents of wood (cellulose, lignins, lignans, oleoresins, etc.) have not been replaced by silicate, but have been infiltrated by specially formulated acidic solutions of aluminosilicate salts that gel in contact with wood matter and form a matrix of silicates within the wood after being left to react slowly for a given period of time in the solution or heat-cured for faster results. Hamilton Hicks of Greenwich, Connecticut, received a patent for his "recipe" for rapid artificial petrifaction of wood under US patent 4,612,050 in 1986.[16] Hicks' recipe consists of highly mineralized water and a sodium silicate solution combined with a dilute acid with a pH of 4.0-5.5. Samples of wood are penetrated with this mineral solution through repeated submersion and applications of the solution. Wood treated in this fashion is - according to the claims in the patent - incapable of being burned and acquires the features of petrified wood. Some uses of this product as suggested by Hicks include use by horse breeders who desire fireproof stables constructed of nontoxic material that would also be resistant to chewing of the wood by horses.[17]

See also


  1. ^ Cedric Mims (21 October 2014). When We Die: The Science, Culture, and Rituals of Death. St. Martin's. p. 190. ISBN 978-1-4668-8385-7.
  2. ^ Babcock, Loren. "Permineralization". Access Science Encyclopedia. McGraw-Hill. Retrieved 29 March 2012.
  3. ^ a b c Perkins, Rogers. "Fossilization: How Do Fossils Form". Fossil Museum. Retrieved Feb 15, 2012.
  4. ^ Sigleo, Anne (1978). Organic geochemistry of silicified wood, Petrified Forest National Park, Arizona. Arizona. pp. 1397–1405. Bibcode:1978GeCoA..42.1397S. doi:10.1016/0016-7037(78)90045-5.
  5. ^ Mustoe, G (2008). Mineralogy and geochemistry of late Eocene silicified wood from Florissant Fossil Beds National Monument, Colorado. Geological Society of America. pp. 127–140.
  6. ^ Leo, R.F.; Barghoorn, E.S. (1976). Silicification of Wood. Harvard University. p. 27.
  7. ^ Viney, Mike. "Permineralization". The Petrified Wood Museum.
  8. ^ "How Does Wood Petrify". National Computational Science in Educati. National Computational Science in Educati. Archived from the original on 17 April 2012. Retrieved 4 April 2012.
  9. ^ "Petrified Wood Gas Station". Google Maps. August 13, 2018.
  10. ^ Kirby, Doug; Ken Smith; Mike Wilkins. "Petrified Wood Gas Station". Roadside America. Retrieved 3 April 2012.
  11. ^ Saltarelli, Mary G. (June 2009). "Irreplaceable Works of Art". Texas Co-op Power Magazine (June 2009). Retrieved 3 April 2012.
  12. ^ Kuban, Glen J. "Dinosaur Valley State Park". Retrieved 3 April 2012.
  13. ^ "Agate House". U.S. Department of the Interior. National Park Service. Retrieved 4 April 2012.
  14. ^ "Process Engineering | Petrified wood yields super ceramics". Chemical Processing. 2005-07-25. Retrieved 2016-09-10.
  15. ^ Orlandini, G.E.; Tempestini R.; Lippi D.; Paternostro F.; Zecchi-Orlandini S.; Villari N. (January 2007). "Bodies of stone: Girolamo Segato (1792-1836)". Italian Journal of Anatomy and Embryology. 112 (1): 13–18. PMID 17580656.
  16. ^ "Sodium silicate composition" (PDF). Retrieved 2016-09-10.
  17. ^ Mike Viney. "Petrified Wood : The Silicification of Wood by Permineralization" (PDF). Retrieved 2016-09-10.
Classical architecture

Classical architecture usually denotes architecture which is more or less consciously derived from the principles of Greek and Roman architecture of classical antiquity, or sometimes even more specifically, from the works of the Roman architect Vitruvius. Different styles of classical architecture have arguably existed since the Carolingian Renaissance, and prominently since the Italian Renaissance. Although classical styles of architecture can vary greatly, they can in general all be said to draw on a common "vocabulary" of decorative and constructive elements. In much of the Western world, different classical architectural styles have dominated the history of architecture from the Renaissance until the second world war, though it continues to inform many architects to this day.

The term "classical architecture" also applies to any mode of architecture that has evolved to a highly refined state, such as classical Chinese architecture, or classical Mayan architecture. It can also refer to any architecture that employs classical aesthetic philosophy. The term might be used differently from "traditional" or "vernacular architecture", although it can share underlying axioms with it.

For contemporary buildings following authentic classical principles, the term New Classical Architecture is sometimes used.


The D'Bari are a fictional alien race appearing in American comic books published by Marvel Comics. They are famous as the people whose star system was destroyed by Phoenix during the Dark Phoenix Saga.

The D'Bari appeared in the 2019 film Dark Phoenix with their leader Vuk portrayed by Jessica Chastain.

Girolamo Segato

Girolamo Segato (13 June 1792 – 3 February 1836) was an Italian naturalist, cartographer, Egyptologist, and anatomist. He is perhaps best known for his work in the artificial petrifaction of human cadavers.Segato was born in the Carthusian monastery of Vedana. As a child, Segato learned basic sciences from Antonio Bagini, a Sospirolo priest. After studying under Bagini, Segato spent a short time as an accountant in Treviso before returning to secondary schooling in Belluno, where his teacher was Tomaso Antonio Catullo.

From 1818 onwards Segato participated in several archaeological expeditions to Egypt, where he became an expert in the techniques of mummification; however, most of his studies undertaken during these trips were lost.

Upon his return to Florence in 1823, Segato developed a technique similar to mummification, but unique: rather than simply removing water from cadavers, Segato's method consisted of what appears to be mineralization or "petrification". His particular technique permitted to save the original colors and features of the textures, besides their elasticity. Most of his works can be found perfectly preserved at the University of Florence, but there is also an example at the Royal Palace of Caserta: a table in the Old Apartments, the surface of which is made with the "petrification" technique.Word soon spread that Segato had acquired knowledge of Egyptian magic. Hampered by the society of his time, he was prompted to destroy all his notes before his death. Segato took to the grave the secret of the technique he developed, which, despite numerous studies and attempts to imitate, remains mysterious. It is said that, on his death, he would reveal his secret to his friend Pellegrini (nicknamed Pellegro), but he died prematurely.

He died in 1836, and was buried in the Basilica of Santa Croce. Today, many of Segato's surviving petrified human remains can be found in the Museum of the Department of Anatomy in Florence.

Holy Boy's Cave

Holy Boy's Cave is a cave in the British Overseas Territory of Gibraltar. It is located on the eastern side of the Rock, near Cave S.

Lady Magnesia

Lady Magnesia (Russian: Леди Магнезия Op. 112) is a 1975 comic opera by Mieczysław Weinberg to his own Russian libretto after Passion, Poison and Petrifaction by George Bernard Shaw.


Lithification (from the Ancient Greek word lithos meaning 'rock' and the Latin-derived suffix -ific) is the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithification is a process of porosity destruction through compaction and cementation. Lithification includes all the processes which convert unconsolidated sediments into sedimentary rocks. Petrifaction, though often used as a synonym, is more specifically used to describe the replacement of organic material by silica in the formation of fossils.

Lost inventions

This is a list of lost inventions:

Greek fire

Damascus steel

Flexible glass


Sloot Digital Coding System

Iron pillar of Delhi, notable for the rust-resistant composition of the metals used in its construction.

Artificial petrifaction of human cadavers invented by Girolamo Segato

Construction technique involved at Saksaywaman where blocks were put into place by carving them precisely. The method used to match precisely the shape of a stone with the adjacent stones is unknown

The high-precision small holes in the blocks of stones at Pumapunku

Paleontology in Washington (state)

Paleontology in Washington refers to paleontological research occurring within or conducted by people from the U.S. state of Washington. Washington has a rich fossil record spanning almost the entire geologic column. Its fossil record shows an unusually great diversity of preservational types including carbonization, petrifaction, permineralization, molds, and cast. Early Paleozoic Washington would come to be home to creatures like archaeocyathids, brachiopods, bryozoans, cephalopods, corals, and trilobites. While some Mesozoic fossils are known, few dinosaur remains have been found in the state. Only about two thirds of the state's land mass had come together by the time the Mesozoic ended. In the Cenozoic the state's sea began to withdraw towards the west, while local terrestrial environments were home to a rich variety of trees and insects. Vertebrates would come to include the horse Hipparion, bison, camels, caribou, oreodonts. Later, during the Ice Age, the northern third of the state was covered in glaciers while creatures like bison, caribou, woolly mammoths, mastodons, and rhinoceros roamed elsewhere in the state. The Pleistocene Columbian Mammoth, Mammuthus columbi is the Washington state fossil.

Passion, Poison, and Petrifaction

Passion, Poison, and Petrifaction is a short play by Bernard Shaw, subtitled The Fatal Gazogene: a Brief Tragedy for Barns and Booths. It is a comic mock-melodrama, written to raise funds for charity. It has been revived occasionally, in tandem with other short works by Shaw or by other playwrights.

Patchwork Girl

The Patchwork Girl (a.k.a. Scraps) is a character from the fantasy Oz Book series by L. Frank Baum. She first appeared in The Patchwork Girl of Oz.

Petrifaction (disambiguation)

Petrifaction is the replacement of organic matter by minerals in fossilization.

Petrifaction may also refer to:

An architectural term – see Classical architecture#Petrification

Petrifaction in mythology and fiction

"Petrified", a song by Fort Minor from The Rising Tied

Petrifaction in mythology and fiction

Petrifaction, or petrification as defined as turning people to stone, is a common theme in folklore and mythology, as well as in some works of modern literature.

Petrified wood

Petrified wood (from the Latin root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. Petrifaction is the result of a tree or tree-like plants having transitioned to stone by a mineralization process that often includes permineralization and replacement. The organic materials making up cell walls have been replicated with minerals (mostly a silicate, such as opal, chalcedony, or quartz). In some instances, the original structure of the stem tissue may be partly retained. Unlike other plant fossils, which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material.

The petrifaction process occurs underground, when wood becomes buried in water saturated sediment or volcanic ash. The presence of water reduces the availability of oxygen which inhibits aerobic decomposition by bacteria and fungi. Mineral-laden water flowing through the sediments may lead to permineralization, which occurs when minerals precipitate out of solution filling the interiors of cells and other empty spaces. During replacement, the plant's cell walls act as a template for mineralization. There needs to be a balance between the decay of cellulose and lignin and mineral templating for cellular detail to be preserved with fidelity. Most of the organic matter often decomposes, however some of the lignin may remain. Silica in the form of Opal-A, can encrust and permeate wood relatively quickly in hot spring environments. However, petrified wood is most commonly associated with trees that were buried in fine grained sediments of deltas and floodplains or volcanic lahars and ash beds. A forest where such material has petrified becomes known as a petrified forest.

Philip Hagemann

Philip Hagemann (born 21 December 1932) is an American composer and conductor.

Hagemann was born in Mount Vernon, Indiana, the son of Harry Philip and Lorene (Knight) Hagemann. He learned to play the piano and the saxophone and took music degrees at Northwestern University in Evanston and Columbia University. From 1954-1956 he served in the US Army. He was a choral conductor in New York, and has published 75 works for choir.He has composed 10 one-act operas and two full-length operas. His first opera was The King Who Saved Himself from Being Saved (1976), a work for children based on a story by John Ciardi. Five of his operas are based on works by George Bernard Shaw; these include (links lead to the original plays) The Music Cure (1984), and Shaw Sings! (1988), which includes The Dark Lady of the Sonnets and Passion, Poison and Petrifaction. Other operas include works based on Henry James's The Aspern Papers, (which premiered at Northwestern University on the same night, 19 November 1988, that Dominic Argento's opera on the same story premiered in Dallas), Edith Wharton's Roman Fever (1989), and Oscar Wilde's The Nightingale and the Rose (2003).Among his other compositions are two choral cycles based on the verses of Ogden Nash, A Musical Menu and A Musical Menagerie. His Christmas choral piece Fruitcake which includes both spoken and sung passages, is a humorous version of the cake recipe, and has sold over 150,000 copies of sheet music.The music critic Anthony Tommasini has written of Hagemann: "His music may lack a strong contemporary profile: his language is essentially tonal and lushly chromatic. Whole-tone melodic patterns recall Ravel". He added that "he injects grittiness into his music through the piling up of clusters and dissonance. He also writes effectively for the voice".


Rhizoliths are root systems that have been encased in mineral matter. Rhizoliths are created through processes of chemical weathering, decomposition, reprecipitation and cementation. Rhizoliths are formed through the transport of dissolved Ca2+ and HCO3− enhancing the CaCO3 precipitation in a diameter of up to several centimeters around the roots. This is possible on calcareous sediments, where high amounts of Ca2+ in the rhizosphere can lead to the formation of encrustations around roots termed rhizoliths.

Sang Kelembai

In Malay folklore, Sang Kelembai (Jawi: سڠ كلمباي) was a giantess generally described as about thrice as big as a normal person, and said to be ugly with thick eyebrows, big fat nose, big elephant ears and fangs. She was feared not only for her looks but also for her power of turning any animal or human being into stone just by greeting them. She is known to have originated from the hinterland of Pahang, but popularly associated with many origin myth especially of geological rocks with peculiar shapes throughout the Malay world. In literature, her petrifaction power is commonly described as Sumpahan Sang Kelembai ('The curse of Sang Kelembai').

The Book of Healing

The Book of Healing (Arabic: کتاب الشفاء Kitāb al-Šifāʾ, Latin: Sufficientia) is a scientific and philosophical encyclopedia written by Abu Ali ibn Sīna (Avicenna) from medieval Persia, near Bukhara in Maverounnahr. Also called The Cure it is intended to "cure" or "heal" ignorance of the soul. Despite its title, it is not concerned with medicine; Avicenna's earlier The Canon of Medicine in 5 volumes had been medical.

This book is Ibn Sina’s major work on science and philosophy. He probably began to compose the al-Shifa in 1014, completed it around 1020, and published it in 1027.The book is divided into four parts: logic, natural sciences, mathematics (a quadrivium of arithmetic, geometry, astronomy, and music), and metaphysics. It was influenced by ancient Greek philosophers, such as Aristotle, Hellenistic thinkers such as Ptolemy, earlier Persian and Muslim scientists and philosophers such as Al-Kindi (Alkindus), Al-Farabi (Alfarabi) and Abū Rayhān al-Bīrūnī.

The Music Cure

The Music Cure, a Piece of Utter Nonsense (1913) is a short comedy sketch by George Bernard Shaw, satirising therapeutic fads of the era and the Marconi scandal of 1912.

Via cava

The Vie Cave (in English excavated roads), also known in Italian as Cavoni, is an impressive road network in southern Europe, found in Spain, Italy, Turkey and as far east as Jordan. In Italy they partly link an Etruscan necropolis and several settlements in the area between Sovana, Sorano and Pitigliano. They consist mainly of trenches of variable width and length, excavated as nearly vertical cliffs in different types of bedrock, sometimes over sixty feet high, possibly serving as a defense system against invaders, wild animals or forces of nature. Although often dated as being carved by pre-Roman civilisations in the first or second millennium BC, the builders and purpose of the road system are largely unclear, and there are indications that they are much older than assumed.

In Italy they are sometimes narrow, sometimes wider cuttings often running deeply through hills and bedrock, and are thought to have changed little since Etruscan times. Their construction is said to have resulted from the wearing through soft tuff but also harder bedrock by iron-rimmed wheels, creating deep ruts that required the road to be frequently recut to a smooth surface. Their dating is mainly deduced from the settlements they pass between, and objects from tombs beside them.. This dating is deemed uncertain by those pointing out the extent of petrifaction of the so-called cart ruts.

In Roman times segments of the Vie Cave became part of a road system that was connected to the main trunk of the Via Clodia, an ancient road linking Rome and Manciano, through the city of Tuscania, which branched off from the Cassia road in Lazio territory. Wider segments are even included in the modern road system.


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