Apatite is a group of phosphate minerals referring to hydroxyapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions in the crystal. The formula of the admixture of the three most common endmembers is written as Ca1062, the crystal unit cell formulae of the individual minerals are written as Ca1062, Ca106F2 and Ca106Cl2; the mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786, although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is mistaken for other minerals; this tendency is reflected in the mineral's name, derived from the Greek word απατείν, which means to deceive or to be misleading. While apatite is most a sedimentary rock, different forms of apatite can be formed in both sedimentary processes, igneous processes, in hydrothermal vents, as well as production by biological systems. Apatite is one of a few minerals used by biological micro-environmental systems.
Apatite is the defining mineral for 5 on the Mohs scale. Hydroxyapatite known as hydroxylapatite, is the major component of tooth enamel and bone mineral. A rare form of apatite in which most of the OH groups are absent and containing many carbonate and acid phosphate substitutions is a large component of bone material. Fluorapatite is more resistant to acid attack. Fluoridated water allows exchange in the teeth of fluoride ions for hydroxyl groups in apatite. Toothpaste contains a source of fluoride anions. Too much fluoride results in dental fluorosis and/or skeletal fluorosis. Fission tracks in apatite are used to determine the thermal histories of orogenic belts and of sediments in sedimentary basins. /He dating of apatite is well established from noble gas diffusion studies for use in determining thermal histories and other, less typical applications such as paleo-wildfire dating. Phosphorite is a phosphate-rich sedimentary rock, that contains between 18% and 40% P2O5; the apatite in phosphorite is present.
The primary use of apatite is in the manufacture of fertilizer – it is a source of phosphorus. It is used as a gemstone. Green and blue varieties, in finely divided form, are pigments with excellent covering power. During digestion of apatite with sulfuric acid to make phosphoric acid, hydrogen fluoride is produced as a byproduct from any fluorapatite content; this byproduct is a minor industrial source of hydrofluoric acid. Fluoro-chloro apatite forms the basis of the now obsolete Halophosphor fluorescent tube phosphor system. Dopant elements of manganese and antimony, at less than one mole-percent — in place of the calcium and phosphorus impart the fluorescence — and adjustment of the fluorine-to-chlorine ratio alter the shade of white produced; this system has been entirely replaced by the Tri-Phosphor system. In the United States, apatite-derived fertilizers are used to supplement the nutrition of many agricultural crops by providing a valuable source of phosphate. Apatites are a proposed host material for storage of nuclear waste, along with other phosphates.
Apatite is infrequently used as a gemstone. Transparent stones of clean color have been faceted, chatoyant specimens have been cabochon-cut. Chatoyant stones are known as cat's-eye apatite, transparent green stones are known as asparagus stone, blue stones have been called moroxite. If crystals of rutile have grown in the crystal of apatite, in the right light the cut stone displays a cat's-eye effect. Major sources for gem apatite are Brazil and Mexico. Other sources include Canada, Czech Republic, India, Mozambique, South Africa, Sri Lanka, the United States. Apatite is found to contain significant amounts of rare-earth elements and can be used as an ore for those metals; this is preferable to traditional rare-earth ores such as monazite, as apatite is not radioactive and does not pose an environmental hazard in mine tailings. However, apatite contains uranium and its radioactive decay-chain nuclides. Apatite is an ore mineral at the Hoidas Lake rare-earth project; the standard enthalpies of formation in the crystalline state of hydroxyapatite, chlorapatite and a preliminary value for bromapatite, have been determined by reaction-solution calorimetry.
Speculations on the existence of a possible fifth member of the calcium apatites family, have been drawn from energetic considerations. Structural and thermodynamic properties of crystal hexagonal calcium apatites, Ca1062, have been investigated using an all-atom Born-Huggins-Mayer potential by a molecular dynamics technique; the accuracy of the model at room temperature and atmospheric pressure was checked against crystal structural data, with maximum deviations of c. 4% for the haloapatites and 8% for hydroxyapatite. High-pressure simulation runs, in the range 0.5-75 kbar, were performed in order to estimate the isothermal compressibility coefficient of those compounds. The deformation of the compressed solids is always elastically anisotropic, with BrAp exhibiting a markedly different behavior from those displayed by HOAp and ClAp. High-pressure p-V data were fitted to the Parsafar-Mason equation of state with an accuracy better than 1%; the monoclinic solid phases Ca1062 and the molten hydroxyapa
Harry Weinberger was an artist based in England. He was'a trenchant defender of traditional painting', who fought passionately against the dominant art school conventions of his day. A painter with a love of colour, Weinberger taught art and illustrated books, he painted people. He preferred to paint objects within them, he never dated his work. The artist died at the age 85 on 10 September 2009. Harry Weinberger was born in the son of a wealthy Jewish industrialist; when Hitler came to power in 1933, Weinberger's father moved the family from Germany to Czechoslovakia. Six years on 20 July 1939, when Weinberger was 15, he and his sister Ina caught the last Kindertransport train to England, where he lived for the rest of his life; as a boy growing up in Germany before the war, Weinberger witnessed several acts of political and racial violence, including the burning of the Reichstag and street brawls. Before the move to Czechoslovakia, Weinberger remembered watching boats of all kinds on the River Spree from the balcony of his parents' house at Bundesratufer 7 – a subject which he returned to in his work, which for him symbolised escape.
Art was around him from an early age. The Weinbergers collected art, a Russian artist, Grisha Oscheroff who lived with the family, taught Harry to paint at an early age, he never lost the obsession. He remembered seeing rich paintings in churches in Czechoslovakia, which fuelled his passion for Russian icons. Weinberger's cousin, the artist Heinz Koppel, four years older than Harry lived in Berlin, moved to Czechoslovakia in 1933 and came to Britain in 1938. Koppel's connections were to prove useful in Weinberger's early career. Weinberger's older brother and two of his uncles were already resident in England by then. On arriving in England, Weinberger boarded at schools in Northamptonshire and Buckinghamshire took a tool-making apprenticeship at a South Wales factory owned by one of his uncles, studied engineering. During this time he took private classes with the Welsh painter and print-maker, Ceri Richards. Weinberger enlisted in the British army towards the end of World War Two, served in Italy.
After a falling out with a commanding officer over his Jewish identity he endured a brief spell in a military prison in Hamburg, but was duly honourably discharged at the end of 1946. After the war Weinberger stated that he wanted to be able to paint, in quiet. In 1951 Weinberger married Barbara Herrmann, an artist and a social historian, his muse in Berlin, the daughter of the architectural historian Wolfgang Herrmann, they had Joanna. Barbara died of cancer in 1996. Weinberger lived in Leamington Spa from 1969 until his death aged 85 on 10 September 2009. On his return to England, Weinberger was awarded an ex-serviceman's grant and moved to London to study under his previous tutor, Ceri Richards, at Chelsea College of Art, he did not do well at Chelsea. Once more, Weinberger looked for private tuition, he resisted studying under Oskar Kokoschka because he thought Kokoschka would try to mould his style too much, so in the end he decided to take lessons from the émigré German artist Martin Bloch, who he admired, who taught his cousin Heinz Koppel.
Bloch was an affirmed expressionist painter who encouraged his students to study in the National Gallery. Weinberger left Chelsea College of Art to join Goldsmiths School of Art. In 1950 he went to Brighton to train as a teacher. Weinberger taught art at schools in London and Reading at a teacher training college in Manchester in the early 1960s and became Head of Painting at Lanchester Polytechnic where he worked for nearly 20 years. In the 1970s, Weinberger won a travelling fellowship from Goldsmiths School of Art to study icon paintings with the advice of the art dealer Richard Temple. Weinberger retired from teaching in 1983 to focus on his studio career. Weinberger had several rules for himself with regard to his work, he painted people except for a few portraits and self-portraits. He preferred to paint interiors and objects within them, he never dated his work. Weinberger said that he would prefer if the viewer focused on the work rather than the time it was made, he did not want comments about whether his style was fashionable or not.
The author of Weinberger's obituary in The Times wrote: "Weinberger's painting had been inspired since the 1940s by his admiration for Matisse and Van Gogh. He painted only what he could see, in the 1950s made impastoed and richly coloured landscapes and portraits. In the 1960s he began to apply his paint more thinly and in patchworks of colour, but in a higher key, with the subjects integrated into the background. From his retirement he lived only to paint, he turned the whole... house into an image of his own work, in colour, furnishing and in the display of art and objects.... His feeling for the pitch and weight of colour was unique, became both more sure and more adventurous." Apart from stories of his early years, Weinberger did not speak much about his Jewish background. He maintained his own interest in his own definition of spiritualism through the artefacts which he collected, he was obsessed with masks African masks and what he called'magic art'
Susa was an ancient city of the Proto-Elamite, First Persian Empire, Seleucid and Sasanian empires of Iran, one of the most important cities of the Ancient Near East. It is located in the lower Zagros Mountains about 250 km east of the Tigris River, between the Karkheh and Dez Rivers; the site now "consists of three gigantic mounds, occupying an area of about one square kilometer, known as the Apadana mound, the Acropolis mound, the Ville Royale mound."The modern Iranian town of Shush is located on the site of ancient Susa. Shush is identified as Shushan, mentioned in the Book of other Biblical books. In Elamite, the name of the city was written Ŝuŝun, etc.. The origin of the word Susa is from the local city deity Inshushinak. Susa was one of the most important cities of the Ancient Near East. In historic literature, Susa appears in the earliest Sumerian records: for example, it is described as one of the places obedient to Inanna, patron deity of Uruk, in Enmerkar and the Lord of Aratta. Susa is mentioned in the Ketuvim of the Hebrew Bible by the name Shushan in Esther, but once each in Nehemiah and Daniel.
According to these texts, Nehemiah lived in Susa during the Babylonian captivity of the 6th century BCE, while Esther became queen there, married to King Ahasuerus, saved the Jews from genocide. A tomb presumed to be that of Daniel is located in the area, known as Shush-Daniel. However, a large portion of the current structure is a much construction dated to the late nineteenth century, ca. 1871. Susa is further mentioned in the Book of Jubilees as one of the places within the inheritance of Shem and his eldest son Elam; the site was examined in 1836 by Henry Rawlinson and by A. H. Layard. In 1851, some modest excavation was done by William Loftus. In 1885 and 1886 Marcel-Auguste Dieulafoy and Jane Dieulafoy began the first French excavations. All of the excavations at Susa, post 1885, were organized and authorized by the French Monarchy. Jacques de Morgan conducted major excavations from 1897 until 1911; the excavations that were conducted in Susa brought many artistic and historical artifacts back to France.
These artifacts filled multiple halls in the Museum of the Louvre throughout the late 1890s and early 1900s. These efforts continued under Roland De Mecquenem until 1914, at the beginning of World War I. French work at Susa resumed after the war, led by De Mecquenem, continuing until World War II in 1940. To supplement the original publications of De Mecquenem the archives of his excavation have now been put online thanks to a grant from the Shelby White Levy Program. Roman Ghirshman took over direction of the French efforts after the end of the war. Together with his wife Tania Ghirshman, he continued there until 1967; the Ghirshmans concentrated on excavating a single part of the site, the hectare sized Ville Royale, taking it all the way down to bare earth. The pottery found at the various levels enabled a stratigraphy to be developed for Susa. During the 1970s, excavations resumed under Jean Perrot. In urban history, Susa is one of the oldest-known settlements of the region. Based on C14 dating, the foundation of a settlement there occurred as early as 4395 BCE.
At this stage it was very large for the time, about 15 hectares. The founding of Susa corresponded with the abandonment of nearby villages. Potts suggests that the settlement may have been founded to try to reestablish the destroyed settlement at Chogha Mish. Chogha Mish was a large settlement, it featured a similar massive platform, built at Susa. Another important settlement in the area is Chogha Bonut, discovered in 1976. Shortly after Susa was first settled over 6000 years ago, its inhabitants erected a monumental platform that rose over the flat surrounding landscape; the exceptional nature of the site is still recognizable today in the artistry of the ceramic vessels that were placed as offerings in a thousand or more graves near the base of the temple platform. Susa's earliest settlement is known as Susa I period. Two settlements named by archaeologists Acropolis and Apadana, would merge to form Susa proper; the Apadana was enclosed by 6m thick walls of rammed earth. Nearly two thousand pots of Susa I style were recovered from the cemetery, most of them now in the Louvre.
The vessels found are eloquent testimony to the artistic and technical achievements of their makers, they hold clues about the organization of the society that commissioned them. Painted ceramic vessels from Susa in the earliest first style are a late, regional version of the Mesopotamian Ubaid ceramic tradition that spread across the Near East during the fifth millennium BC. Susa I style was much a product of the past and of influences from contemporary ceramic industries in the mountains of western Iran; the recurrence in close association of vessels of three types—a drinking goblet or beaker, a serving dish, a small jar—implies the consumption of three types of food thought to be as necessary for life in the afterworld as it is in this one. Ceramics of these shapes, which were painted, constitute a large proportion of the vessels from the cemetery. Others are coarse cooking-type jars and bowls with simple bands