Porphyry is a variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz, dispersed in a fine-grained feldspathic matrix or groundmass. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. The matrix or groundmass of rock is the fine-grained mass of material in which larger grains or Crystals are embedded The larger crystals are called phenocrysts. A phenocryst is a relatively large and usually conspicuous Crystal distinctly larger than the grains of the rock groundmass of a Porphyritic Igneous In its non-geologic, traditional use, the term "porphyry" refers to the purple-red form of this stone, valued for its appearance.
The term "porphyry" is from Greek and means "purple". Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Purple is a general term for the range of shades of Color occurring between Red and Blue. Purple was the color of royalty, and the "Imperial Porphyry" was a deep brownish purple igneous rock with large crystals of plagioclase. Plagioclase is a very important series of tectosilicate Minerals within the Feldspar family This rock was prized for various monuments and building projects in Imperial Rome and later. The Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial Pliny's Natural History affirmed that the "Imperial Porphyry" had been discovered at an isolated site in Egypt in AD 18, by a Roman legionnaire named Caius Cominius Leugas (Werner 1998). Naturalis Historia ( Latin for "Natural History" is an Encyclopedia written Circa AD 77 by Pliny the Elder. It came from a single quarry in the Eastern Desert of Egypt, from 600 million year old andesite of the Arabian-Nubian Shield. The Stone quarries of ancient Egypt (now archaeological sites once produced quality stone for the construction of decorative monuments such as Sculptures and Obelisks The Eastern Desert refers to the desert east of the river Nile, between the Nile and the Red Sea. This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. For the extinct cephalopod genus see Andesites. Andesite (ˈændəsaɪt is an igneous, Volcanic rock, of intermediate The Arabian-Nubian Shield (ANS is an exposure of Precambrian crystalline rocks on the flanks of the Red Sea. The road from the quarry westward to Qena (Roman Maximianopolis) on the Nile, which Ptolemy put on his second-century map, was described first by Strabo, and it is to this day known as the Via Porphyrites, the Porphyry Road, its track marked by the hydreumata, or watering wells that made it viable in this utterly dry landscape. Claudius Ptolemaeus ( Greek: Klaúdios Ptolemaîos; after 83 &ndash ca Strabo ( Greek: Στράβων 63/64 BC – ca AD 24 was a Greek historian, geographer and philosopher. In Hellenistic and Roman Arabia and Egypt a hydreuma (plural hydreumata) was an enclosed (and often fortified "watering station" (Greek Porphyry was extensively used in Byzantine imperial monuments, for example in Hagia Sophia and in the "Porphyra", the official delivery room for use of pregnant Empresses in the Great Palace of Constantinople. Hagia Sophia (Ayasofya Αγία Σοφία " Holy Wisdom " Sancta Sophia or Sancta Sapientia) is a former patriarchal Basilica, later The Byzantine Great Palace of Constantinople, (Μέγα Παλάτιον Turkish: Büyük Saray also known as the Sacred Palace ( Latin
After the fourth century the quarry was lost to sight for many centuries. The scientific members of the French Expedition under Napoleon sought for it in vain, and it was only when the Eastern Desert was reopened for study under Muhammad Ali that the site was rediscovered by Burton and Wilkinson in 1823. Napoleon Bonaparte (15 August 1769 – 5 May 1821 was a French military and political leader who had a significant impact on the History of Europe. This article is about the leader of Egypt For other people named Muhammad Ali or Mehmet Ali see Muhammad Ali (disambiguation and Mehemet Ali (disambiguation Sir John Gardner Wilkinson ( October 5, 1797 &ndash October 29, 1875) was a well-known English traveller writer and pioneer Egyptologist Year 1823 ( MDCCCXXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Common
Subsequently the name was given to igneous rocks with large crystals. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Porphyry now refers to a texture of igneous rocks. Rock microstructure includes the texture of a rock and the small scale rock structures Its chief characteristic is a large difference between the size of the tiny matrix crystals and other much larger crystals, called phenocrysts. A phenocryst is a relatively large and usually conspicuous Crystal distinctly larger than the grains of the rock groundmass of a Porphyritic Igneous Porphyries may be aphanites or phanerites, that is, the groundmass may have invisibly small crystals, like basalt, or the individual crystals of the groundmass may be easily distinguished with the eye, as in granite. A phanerite is an Igneous rock having the grains of its essential minerals large enough to be seen macroscopically i Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. Many types of igneous rocks may display porphyrytic texture.
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Formation
Porphyry deposits are formed when a column of rising magma is cooled in two stages. Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet In the first stage, the magma is cooled slowly deep in the crust, creating the large crystal grains, with a diameter of 2 mm or more. In the final stage, the magma is cooled rapidly at relatively shallow depth or as it erupts from a volcano, creating small grains that are usually invisible to the unaided eye. Plate tectonics and hotspots Divergent plate boundaries At the The cooling also leads to a separation of dissolved metals into distinct zones. This process is one of the main reasons for the existence of rich, localised metal ore deposits such as those of gold, copper, molybdenum, lead, tin, zinc and tungsten. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74
In history
As early as 1850 BC on Crete in Minoan Knossos there were large columns made of porphyry. Crete ( Greek: Κρήτη transliteration: Krētē, modern transliteration Kriti) is the largest of the Greek islands and the Knossos (alternative spellings Knossus, Cnossus, Greek Κνωσός kno̞ˈso̞s also known as the Knossos Palace is the largest [1] All the porphyry columns in Rome, the red porphyry togas on busts of emperors, the porphyry panels in the revetment of the Pantheon,[2] as well as the altars and vases and fountain basins reused in the Renaissance and dispersed as far as Kiev, all came from the one quarry at Mons Porpyritis[3] ("Porphyry Mountain", the Arabic Jabal Abu Dukhan), which seems to have been worked intermittently between 29 and 335 AD,[4] when Constantine I celebrated the founding of his capital Constantinople with a 30-meter (100') pillar, built of seven stacked porphyry drums, which still stands. This article is about the aviation term for the Roman garment see Toga. An emperor (from the Latin " Imperator " is a (male Monarch, usually the sovereign ruler of an Empire or another type of The Pantheon ( Latin Pantheon, from Greek Πάνθειον Pantheon, meaning "Temple of all the gods" is a building in Rome The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere Kiev, also known as Kyiv ( Ukrainian:, Kyiv, ˈkɪjiw Russian:, Kiyev; see also Cities' alternative names) is the Year 29 was a Common year starting on Saturday (link will display the full calendar of the Julian calendar. Events By Place Roman Empire 19 September — Dalmatius is raised to the rank of Caesar. Flavius Valerius Aurelius Constantinus (27 February ca. 272 &ndash 22 May 337 commonly known as Constantine I, Constantine the Great, or Saint Constantine Constantinople (Κωνσταντινούπολις Konstantinoúpolis, or gr ἡ Πόλις hē Polis, Latin: la CONSTANTINOPOLIS A triumphant last use were the eight monolithic columns of porphyry that support exedrae (semicircular niches) in Hagia Sophia. In Architecture, an exedra is a semicircular recess often crowned by a half- Dome, which is usually set into a building's facade Hagia Sophia (Ayasofya Αγία Σοφία " Holy Wisdom " Sancta Sophia or Sancta Sapientia) is a former patriarchal Basilica, later Justinian's chronicler, Procopius, called the columns "a meadow with its flowers in full bloom, surely to make a man marvel at the purple of some and at those on which the crimson glows. " (noted by Werner).
Byzantine historians distinguish two sorts of emperors: those who won power through a coup and those "born to the purple". These porphyrogenites were born to the imperial family in a room in the Great Palace veneered with purple porphyry, as described by Anna Comnena, daughter of the eleventh century emperor Alexius I. Porphyrogennētos or Porphyrogenitus (Greek Πορφυρογέννητος literally "born in the Purple" was a title given to a son or daughter ( Porphyrogenneta The Byzantine Great Palace of Constantinople, (Μέγα Παλάτιον Turkish: Büyük Saray also known as the Sacred Palace ( Latin Anna Komnene or Comnena (Greek Άννα Κομνηνή Anna Komnēnē December 1, 1083 &ndash1153 was a Byzantine princess and scholar daughter of
The imperial family were entombed in the purple as well, beginning with Nero, who was the first to be immured in a porphyry sarcophagus. Nero Claudius Caesar Augustus Germanicus ( December 15, 37 – June 9, 68) born Lucius Domitius Ahenobarbus, also called Roman sarcophagi were re-used for imperial burials in Sicily: the porphyry sarcophagi of Holy Roman Emperors Frederick II and Henry IV and king William I of Sicily and the Empress Constance are preserved in the cathedrals of Palermo and Monreale. Frederick II ( December 26, 1194 &ndash December 13, 1250) of the Hohenstaufen dynasty was a Pretender to the title Henry IV ( November 11, 1050 &ndash August 7, 1106) was King of Germany from 1056 and Holy Roman Emperor from 1084 until William I ( 1131 - May 7 1166) called the Bad or the Wicked, was the second King of Sicily, ruling from his father's death Constance of Sicily (1154 &ndash November 27, 1198) was the heiress of the Norman kings of Sicily and the wife of Henry VI Holy Roman Emperor Palermo ( Sicilian: Palermu, Greek: Panormus, al-Madinah during Muslim rule is a historic City in Monreale ( Sicilian: Murriali) is a town and Comune in the Province of Palermo, in Sicily, Italy,
The Romans used the Imperial porphyry for the monolithic pillars of Baalbek's Temple of Heliopolis in Lebanon. Baalbek (بعلبك is a town in the Bekaa Valley of Lebanon, altitude 1170 m (3850 ft situated east of the Litani River. Lebanon (ˈlɛbənɒn Arabic: ar لبنان Lubnān) officially the Republic of Lebanon or Lebanese Republic (ar الجمهورية اللبنانية Today there are at least 134 porphyry columns in buildings around Rome, all reused from imperial times, since the stone is not naturally present in Italy, and countless altars, basins and other objects.
Porphyry was used extensively for decoration in Germany, Poland, and Czechoslovakia. The Protestant Cathedral of Magdeburg (Magdeburger Dom officially called the Cathedral of Saints Catherine and Maurice (Dom zu Magdeburg St Hurghada ( ar: Al Ghardaqah, الغردقة is an Egyptian City and a tourist center on the Red Sea. This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Poland (Polska officially the Republic of Poland Czechoslovakia may also refer to what is now the Czech Republic and Slovakia. This can be seen in the Mannerist style sculpted portal outside the chapel entrance in Colditz Castle. Mannerism is a period of European art which emerged from the later years of the Italian High Renaissance around 1520. Colditz Castle is a Castle in the town of Colditz near Leipzig, Dresden, and Chemnitz in the state of Saxony
Louis XIV King of France obtained the largest collection of porphyry by acquiring the Borghese collection. Early years Birth and ancestry Louis XIV was born in the Château de Saint-Germain-en-Laye on September 5 1638 and bore the Heir apparent This article is about the country For a topic outline on this subject see List of basic France topics. Borghese is the surname of a family of Italian noble and papal background originating in Siena as the Borghese or Borghesi where they came to prominence in the 13th century
In 1840, Bonapartists recovered the body of Napoleon I from Saint Helena and intended to bury it in a porphyry sarcophagus in Les Invalides, Paris. In French political history Bonapartism has two meanings In a strict sense this term refers to people who Napoleon Bonaparte (15 August 1769 – 5 May 1821 was a French military and political leader who had a significant impact on the History of Europe. Les Invalides in Paris, France, is a complex of buildings in the city's 7th arrondissement containing Museums and monuments all relating However, the Egyptian quarry was not available and a similar red quartzite from Finland was chosen, in spite of its purchase from the Russian Empire, an enemy of France. Quartzite (from German Quarzit) not to be confused with the Mineral Quartz, is a hard Metamorphic rock which was originally
Example Porphyries
- Dacite porphyry
- Trachyte/latite porphyry
- Diorite porphyry
- Granite porphyry
- Rhyolite porphyry
- basalt porphyry
- see also porphyritic texture
- see also list of rock textures
Rhomb porphyry
Rhomb porphyry is a volcanic rock with gray-white large porphyritic rhomb shaped phenocrysts enbedded in a very fine grained red-brown matrix. Dacite ( deɪsaɪt) is an igneous, volcanic rock with a high iron content Trachyte is an Igneous, Volcanic rock with an Aphanitic to Porphyritic texture Latite is an igneous, volcanic ( extrusive) rock, with Aphanitic -aphyric to aphyric- Porphyritic texture Diorite (ˈdaɪəraɪt is a grey to dark grey intermediate intrusive Igneous rock composed principally of Plagioclase Feldspar (typically Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. This page is about a volcanic rock For the ghost town see Rhyolite Nevada, and for the satellite system see Rhyolite/Aquacade. Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. This page is intended to be a list of rock textural and morphological terms Volcanic rock is an Igneous rock of volcanic origin Texture Volcanic rocks are usually fine-grained or Aphanitic to glassy in Porphyry is a variety of Igneous rock consisting of large-grained Crystals such as Feldspar or Quartz, dispersed in a fine-grained In Geometry, a rhombus (from Ancient Greek ῥόμβος - rrhombos “rhombus spinning top” (plural rhombi or rhombuses A phenocryst is a relatively large and usually conspicuous Crystal distinctly larger than the grains of the rock groundmass of a Porphyritic Igneous The matrix or groundmass of rock is the fine-grained mass of material in which larger grains or Crystals are embedded The composition of rhomb porphyry place it in the trachyte - latite classification of the QAPF diagram. Trachyte is an Igneous, Volcanic rock with an Aphanitic to Porphyritic texture Latite is an igneous, volcanic ( extrusive) rock, with Aphanitic -aphyric to aphyric- Porphyritic texture A QAPF diagram is a double triangle Diagram which is used to classify Igneous rocks based on mineralogic composition
Rhomb porphyry lavas are known only from three rift areas: The East African Rift (including Mount Kilimanjaro), Mount Erebus near the Ross Sea in Antarctica, and the Oslo graben in Norway. Lava is molten rock expelled by a Volcano during an eruption When first expelled from a volcanic vent it is a Liquid at Temperatures In Geology, a rift is a place where the Earth 's crust and Lithosphere are being pulled apart and is an example of Extensional tectonics The East African Rift is part of the larger Great Rift Valley. Mount Erebus in Antarctica is the southernmost active Volcano on Earth NOAA Ross seajpg|thumb|200px|thumb|Ice in the Ross Sea Antarctica]] The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria The Oslo Graben or Oslo Rift is a Graben formed during a geologic rifting event in Permian time Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional
References
- ^ C. Michael Hogan, Knossos fieldnotes, Modern Antiquarian (2007)
- ^ A visit to the ancient Imperial Porphyry quarries in Egypt. Saudi Aramco World Louis Werner, "Via Porphyrites" November/December 1998
- ^ University of Southhampton, Mons Porphyrites quarries, Egypt
- ^ Rushdi Said, Al-Ahram Weekly, 18 - 24 February 1999 Issue No. 417, Roman occupation of the Eastern Desert of Egypt and the Imperial Porphyry quarries
External links
- Pictures of the Mons Porphyrites, Red Sea, Egypt.
- Rhomb porphyry lavas
- Flash showing rhomb porphyry formation
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