Neolithic flint mines of Spiennes
The mines were active during the mid and late Neolithic between 4,300 and 2,200 BC. Declared to be remarkable for the diversity of technological solutions used for extraction the site, discovered in 1843, the first excavations were undertaken during railway construction in 1867 and intermittent excavations have been carried out up to the present day. The Mines of Spiennes cover some 100 ha of downland four miles south-east of the city of Mons, the site is dotted with millions of scraps of worked flint and numerous mining pits, that Neolithic settlers have gradually turned into vertical mine shafts to depths of over 10 m. Research has illustrated Neolithic techniques for the cutting of the flint and the extraction of large slabs of flint, the nodules were extracted using flint picks. The stones were knapped into rough-out shapes of axes, the SILEXS Interpretive Centre has opened in spring 2015. The rough-outs were exchanged over an area, about 150 km. Polishing strengthens the product, making the axe- or adze-head last longer.
The smooth surface aids the cutting action by lowering friction with the wood, the axes were used initially for forest clearance during the Neolithic period, and for shaping wood for structural applications, such as timber for huts and canoes. The site has been compared with Grimes Graves and Cissbury in the United Kingdom, and Krzemionki in Poland, different hard rocks were used for the polished stone axes. Examples include the Langdale axe industry and Tievebulliagh, guillaume, Ph. Lipinski & A. Masson, Les mines de silex néolithiques de la Meuse dans le contexte européen. Musées de la Meuse, Sampigny 1987, F. Gosselin, Un site dexploitation du silex à Spiennes, au lieu-dit Petit-Spiennes. F. Hubert, Une minière néolithique à silex au Camp-à-Cayaux de Spiennes, F. Hubert, Lexploitation préhistorique du silex à Spiennes. Ministère de la Région wallonne, Direction générale de lAménagement du Territoire, du Logement et du Patrimoine, R. Shepherd, Prehistoric Mining and Allied Industries. Société de recherches préhistoriques en Hainaut, Minières néolithiques à Spiennes,1997 ICOMOS evaluation Collet, H.
Les mines néolithiques de Spiennes, état des connaissances et perspectives de recherche. Section 10, The Neolithic in the Near East and Europe, actes du XIVème congrès UISPP, Université de Liège, Belgique,2 –8 septembre 2001 H. Collet, A. Hauzeur & J. Lech,2008. The prehistoric flint mining complex at Spiennes on the occasion of its discovery 140 years ago In P. Allard, F. Bostyn, flint mining in Prehistoric Europe, Interpreting the archaeological records. European Association of Archaeologists, 12th Annual Meeting, Poland, 19–24 September 2006, H. Collet,2014. Les minières néolithiques de silex de Spiennes
The Areni-1 cave complex is located near the Areni village in southern Armenia along the Arpa River. In 2010, it was announced that the earliest known shoe was found at the site, in January 2011, the earliest known winery in the world was announced to have been found. Also in 2011, the discovery of a straw skirt dating to 3900 BC was reported, in 2009, the oldest brain was discovered
Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes, the English word karst was borrowed from German Karst in the late 19th century. The German word came into use before the 19th century, according to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic. Scholars disagree, however, on whether the German word was borrowed from Slovene, the Slovene common noun kras was first attested in the 18th century, and the adjective form kraški in the 16th century. The Slovene words arose through metathesis from the reconstructed form *korsъ, the word is of Mediterranean origin, believed to derive from some Romanized Illyrian base.
It has been suggested that the word may derive from the Proto-Indo-European root karra- rock, the name may be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps to Latin Carusardius. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, if this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power. The carbonic acid that causes karstic features is formed as rain passes through the atmosphere picking up carbon dioxide, once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate. The oxidation of sulfides leading to the formation of acid can be one of the corrosion factors in karst formation.
As oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, sulfuric acid reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is, This reaction chain forms gypsum, the karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath. On exposed surfaces, small features may include solution flutes, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements and karst valleys, mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground systems and extensive caves. Some of the most dramatic of these formations can be seen in Thailands Phangnga Bay, calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide.
Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time, in caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals
Henri Édouard Prosper Breuil, often referred to as Abbé Breuil, was a French Catholic priest, anthropologist and geologist. Breuil was born at Mortain, Manche and was the son of Albert Breuil, magistrate and he received his education at the Seminary of St. Sulpice and the Sorbonne and was ordained in 1900 but was given permission to pursue his research interests. He was a man of religious faith and learning. In 1904 Breuil had recognised that a pair of 13, 000-year-old carvings of reindeer at the British Museum were in one composition. He assumed a post as lecturer at the University of Fribourg in 1905, Breuil was a competent draughtsman, faithfully reproducing the cave paintings he encountered. In 1924 he was awarded the Daniel Giraud Elliot Medal from the National Academy of Sciences and he published many books and monographs, introducing the caves of Lascaux and Altamira to the general public and becoming a member of the Institut de France in 1938. Breuil visited the Peking Man excavations at Zhoukoudian, China in 1931, in 1929, when already a recognised authority on North African and European Stone Age art, he attended a congress on prehistory in South Africa.
At the invitation of prime minister Jan Smuts he returned there in 1942, during his South African stay he studied rock art in Lesotho, the eastern Free State and in the Natal Drakensberg. He undertook three expeditions to South West Africa and Rhodesia between 1947 and 1950 and he described this period as the most thrilling years of my research life. In 1953 he announced his discovery of a painting about 6000 years old, subsequently dubbed The White Lady, Breuil returned to France in 1952 and produced a series of publications sponsored by the South African Government. Breuils books contain valuable photographs and sketches of the art works at the sites he visited but are marred by official South African racism, Breuil developed elaborate scenarios to attribute white authorship to the paintings he studied. His contributions to European and African archaeology were considerable and recognised by the award of honorary doctorates from no fewer than six universities and he died at LIsle-Adam, Val-dOise, France.
The Cave of Altamira at Santillana del Mar, four Hundred Centuries of Cave Art. The White Lady of the Brandberg, london and Faber, New York, Frederick A. Praeger,1955. The Men of the Old Stone Age, New York, St. Martins Press,1965. The Paintings of the Tsisab Ravine The Rock Paintings of Southern Africa Broderick, New York, William Morrow & Company,1963. Un préhistorien dans le siècle, CNRS Éditions,2011 Présentation du livre Straus, lAbbé Henri Breuil, Bulletin of the History of Archaeology. LAbbé Henri Breuil, Pope of Paleolithic Prehistory, Homenaje al Dr. Joaquín González Echegaray, Museo y Centro de Investigación de Altamira,1994, pp. 189–198
Among some of the best-known Upper Paleolithic works of art depicted are primarily large animals, typical local and contemporary fauna that corresponds with the fossil record. The paintings are the combined effort of many generations, and despite continuing debate, Lascaux was inducted into the UNESCO World Heritage Sites list in 1979, as element of the Prehistoric Sites and Decorated Caves of the Vézère Valley. On September 12,1940, the entrance to the Lascaux Cave was discovered by 18 year old Marcel Ravidat, Ravidat returned to the scene with three friends, Jacques Marsal, Georges Agnel, and Simon Coencas, and entered the cave via a long shaft. The teenagers discovered that the walls were covered with depictions of animals. Galleries that suggest continuity. Those include the Hall of the Bulls, the Passageway, the Shaft, the Nave, the Apse, the cave complex was opened to the public in 1948. By 1955, carbon dioxide, heat and other contaminants produced by 1,200 visitors per day had visibly damaged the paintings, as air condition deteriorated fungi and lichen increasingly infested the walls.
Consequently the cave was closed to the public in 1963, the paintings were restored to their original state, a full range of Lascauxs parietal art is presented at the Centre of Prehistoric Art at Le Parc du Thot. Ochroconis lascauxensis is a species of fungus of the Ascomycota phylum, in May 2012 officially described and named after the locality of its first emergence, the Lascaux cave. It was along with a closely related second species Ochroconis anomala, first observed in 2000 inside the cave, no official announcement on the effect and/or progress of attempted treatments has ever been made. As of 2008, the cave contained black mold, in January 2008, authorities closed the cave for three months even to scientists and preservationists. A single individual was allowed to enter the cave for 20 minutes once a week to monitor climatic conditions, in 2009 it was announced, Mould problem stable. In 2011 the fungus seemed to be in retreat after the installment of an additional, in its sedimentary composition, the Vézère drainage basin covers one fourth of the département of the Dordogne, the northernmost region of the Black Périgord.
Before joining the Dordogne River near Limeuil, the Vézère flows in a south-westerly direction, at its centre point, the rivers course is marked by a series of meanders flanked by high limestone cliffs that determine the landscape. The Lascaux valley is located some distance from the concentrations of decorated caves and inhabited sites. This is the highest concentration in western Europe, the cave contains nearly 2,000 figures, which can be grouped into three main categories, human figures, and abstract signs. The paintings contain no images of the landscape or the vegetation of the time. Charcoal may have used but seemingly to a sparing extent. In other areas, the colour was applied by spraying the pigments by blowing the mixture through a tube, where the rock surface is softer, some designs have been incised into the stone
Belgium, officially the Kingdom of Belgium, is a sovereign state in Western Europe bordered by France, the Netherlands, Germany and the North Sea. It is a small, densely populated country which covers an area of 30,528 square kilometres and has a population of about 11 million people. Additionally, there is a group of German-speakers who live in the East Cantons located around the High Fens area. Historically, the Netherlands and Luxembourg were known as the Low Countries, the region was called Belgica in Latin, after the Roman province of Gallia Belgica. From the end of the Middle Ages until the 17th century, Belgium is a federal constitutional monarchy with a parliamentary system of governance. It is divided into three regions and three communities, that exist next to each other and its two largest regions are the Dutch-speaking region of Flanders in the north and the French-speaking southern region of Wallonia. The Brussels-Capital Region is a bilingual enclave within the Flemish Region. A German-speaking Community exists in eastern Wallonia, Belgiums linguistic diversity and related political conflicts are reflected in its political history and complex system of governance, made up of six different governments.
Upon its independence, declared in 1830, Belgium participated in the Industrial Revolution and, during the course of the 20th century, possessed a number of colonies in Africa. This continuing antagonism has led to several far-reaching reforms, resulting in a transition from a unitary to a federal arrangement during the period from 1970 to 1993. Belgium is a member of the Eurozone, NATO, OECD and WTO. Its capital, hosts several of the EUs official seats as well as the headquarters of major international organizations such as NATO. Belgium is a part of the Schengen Area, Belgium is a developed country, with an advanced high-income economy and is categorized as very high in the Human Development Index. A gradual immigration by Germanic Frankish tribes during the 5th century brought the area under the rule of the Merovingian kings, a gradual shift of power during the 8th century led the kingdom of the Franks to evolve into the Carolingian Empire. Many of these fiefdoms were united in the Burgundian Netherlands of the 14th and 15th centuries, the Eighty Years War divided the Low Countries into the northern United Provinces and the Southern Netherlands.
The latter were ruled successively by the Spanish and the Austrian Habsburgs and this was the theatre of most Franco-Spanish and Franco-Austrian wars during the 17th and 18th centuries. The reunification of the Low Countries as the United Kingdom of the Netherlands occurred at the dissolution of the First French Empire in 1815, although the franchise was initially restricted, universal suffrage for men was introduced after the general strike of 1893 and for women in 1949. The main political parties of the 19th century were the Catholic Party, French was originally the single official language adopted by the nobility and the bourgeoisie
Petroglyphs are images created by removing part of a rock surface by incising, carving, or abrading, as a form of rock art. Outside North America, scholars often use such as carving, engraving. Petroglyphs are found world-wide, and are associated with prehistoric peoples. The word comes from the Greek word petro-, theme of the word meaning stone, and glyphein meaning to carve. The term petroglyph should not be confused with petrograph, which is an image drawn or painted on a rock face, both types of image belong to the wider and more general category of rock art or parietal art. Petroforms, or patterns and shapes made by large rocks. Inukshuks are unique, and found only in the Arctic and they are a category of rock art, and sometimes found in conjunction with rock-cut architecture. However, they tend to be omitted in most works on rock art, a few such works exploit the natural contours of the rock and use them to define an image, but they do not amount to man-made reliefs. Rock reliefs have been made in many cultures, and were important in the art of the Ancient Near East.
Rock reliefs are generally large, as they need to be to make an impact in the open air. Most have figures that are over life-size, and in many the figures are multiples of life-size, the vertical relief is most common, but reliefs on essentially horizontal surfaces are found. The term typically excludes relief carvings inside caves, whether natural or themselves man-made, natural rock formations made into statues or other sculpture in the round, most famously at the Great Sphinx of Giza, are usually excluded. Reliefs on large boulders left in their location, like the Hittite İmamkullu relief, are likely to be included. Some petroglyphs are dated to approximately the Neolithic and late Upper Paleolithic boundary, about 10,000 to 12,000 years ago, if not earlier. Sites in Australia have petroglyphs that are estimated to be as much as 27,000 years old, around 7,000 to 9,000 years ago, other precursors of writing systems, such as pictographs and ideograms, began to appear. Petroglyphs were still common though, and some cultures continued using them much longer, petroglyphs have been found in all parts of the globe except Antarctica with highest concentrations in parts of Africa, Siberia, southwestern North America and Australia.
There are many theories to explain their purpose, depending on their location, some petroglyphs are thought to be astronomical markers and other forms of symbolic communication, including a form of pre-writing. Petroglyph maps may show trails, symbols communicating time and distances traveled, as well as the terrain in the form of rivers, landforms
Bosnia and Herzegovina
Bosnia and Herzegovina, sometimes called Bosnia-Herzegovina, and, in short, often known informally as Bosnia, is a country in Southeastern Europe located on the Balkan Peninsula. Sarajevo is the capital and largest city, in the central and eastern interior of the country the geography is mountainous, in the northwest it is moderately hilly, and the northeast is predominantly flatland. The inland is a larger region and has a moderate continental climate, with hot summers and cold. The southern tip of the country has a Mediterranean climate and plain topography and Herzegovina is a region that traces permanent human settlement back to the Neolithic age and after which it was populated by several Illyrian and Celtic civilizations. Culturally and socially, the country has a rich history, the Ottomans brought Islam to the region, and altered much of the cultural and social outlook of the country. This was followed by annexation into the Austro-Hungarian Monarchy, which lasted up until World War I.
In the interwar period, Bosnia was part of the Kingdom of Yugoslavia and after World War II, following the dissolution of Yugoslavia, the country proclaimed independence in 1992, which was followed by the Bosnian War, lasting until late 1995. The country is home to three ethnic groups or, constituent peoples, as specified in the constitution. Bosniaks are the largest group of the three, with Serbs second and Croats third, a native of Bosnia and Herzegovina, regardless of ethnicity, is identified in English as a Bosnian. The terms Herzegovinian and Bosnian are maintained as a rather than ethnic distinction. Moreover, the country was simply called Bosnia until the Austro-Hungarian occupation at the end of the 19th century and Herzegovina has a bicameral legislature and a three-member Presidency composed of a member of each major ethnic group. The Federation of Bosnia and Herzegovina is itself complex and consists of 10 cantons, the country has been a member of the Council of Europe since April 2002 and a founding member of the Mediterranean Union upon its establishment in July 2008.
The name is believed to have derived from the hydronym of the river Bosna coursing through the Bosnian heartland. According to philologist Anton Mayer the name Bosna could be derived from Illyrian Bass-an-as which would be a diversion of the Proto-Indo-European root bos or bogh, meaning the running water. According to English medievalist William Miller the Slavic settlers in Bosnia adapted the Latin designation Basante, to their own idiom by calling the stream Bosna, the name Herzegovina originates from Bosnian magnate Stephen Vukčić Kosačas title, Herceg of Hum and the Coast. Hum, formerly Zahumlje, was a medieval principality that was conquered by the Bosnian Banate in the first half of the 14th century. Bosnia is located in the western Balkans, bordering Croatia to the north and west, Serbia to the east and it has a coastline about 20 kilometres long surrounding the city of Neum. It lies between latitudes 42° and 46° N, and longitudes 15° and 20° E, the countrys name comes from the two regions Bosnia and Herzegovina, which have a very vaguely defined border between them
France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lille, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established.
The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity.
In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine.
Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, granular, or massive, depending on the method of formation.
Crystals of calcite, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
It is located near the commune of Vallon-Pont-dArc on a limestone cliff above the former bed of the Ardèche River, in the Gorges de lArdèche. Discovered on December 18,1994, it is considered one of the most significant prehistoric art sites and its paintings, along with those of Lascaux and the Cave of Altamira, have been dubbed a prehistoric Sistine Chapel. The cave was first explored by a group of three speleologists, Eliette Brunel-Deschamps, Christian Hillaire, and Jean-Marie Chauvet for whom it was named, Chauvet has a detailed account of the discovery. In addition to the paintings and other evidence, they discovered fossilized remains, prints. Further study by French archaeologist Jean Clottes has revealed much about the site, the dates have been a matter of dispute but a study published in 2012 supports placing the art in the Aurignacian period, approximately 32, 000–30,000 years BP. The cave is situated above the course of the Ardèche River before the Pont dArc opened up. The gorges of the Ardèche region are the site of numerous caves, the Chauvet Cave is uncharacteristically large and the quality and condition of the artwork found on its walls have been called spectacular.
Based on radiocarbon dating, the cave appears to have used by humans during two distinct periods, the Aurignacian and the Gravettian. Most of the dates to the earlier, era. After the childs visit to the cave, evidence suggests that due to a landslide which covered its historical entrance, the footprints may be the oldest human footprints that can be dated accurately. The soft, clay-like floor of the cave retains the paw prints of cave bears along with large, fossilized bones are abundant and include the skulls of cave bears and the horned skull of an ibex. A set of prints of a young child and a wolf or dog walking side by side was found in this cave. This information suggests the origin of the dog could date to before the last Ice Age. Hundreds of animal paintings have been catalogued, depicting at least 13 different species, there are paintings of rhinoceroses. Typical of most cave art, there are no paintings of human figures. Above the Venus, and in contact with it, is a bison head, there are a few panels of red ochre hand prints and hand stencils made by blowing pigment over hands pressed against the cave surface.
Abstract markings—lines and dots—are found throughout the cave, there are two unidentifiable images that have a vaguely butterfly or avian shape to them. This combination of subjects has led some students of art and cultures to believe that there was a ritual, shamanic
Ochre (/ˈoʊkər/ OH-kər, from Greek, ὠχρός, ōkhrós, or ocher, is a natural earth pigment containing hydrated iron oxide, which ranges in color from yellow to deep orange or brown. It is the name of the produced by this pigment. A variant of ochre containing an amount of hematite, or dehydrated iron oxide, has a reddish tint known as red ochre. Ochre is a family of pigments, which includes yellow ochre, red ochre, purple ochre, sienna. The major ingredient of all the ochres is iron oxide-hydroxide, known as limonite, which gives them a yellow color. Yellow ochre, FeO·nH 2O, is a hydrated iron hydroxide called gold ochre Red ochre, Fe 2O3, takes its color from the mineral hematite. Purple ochre, is identical to red ochre chemically but of a different hue caused by different light diffraction properties associated with an average particle size. Brown ochre, FeO, is a hydrated iron oxide. Sienna contains both limonite and an amount of manganese oxide, which makes it darker than ochre. Umber pigments contain a proportion of manganese which make them a dark brown.
When natural sienna and umber pigments are heated, they are dehydrated and some of the limonite is transformed into hematite, giving them more reddish colors, called burnt sienna and burnt umber. Ochres are non-toxic, and can be used to make an oil paint that dries quickly, modern ochre pigments often are made using synthetic iron oxide. Pigments which use natural ochre pigments indicate it with the name PY-43 on the label, pieces of ochre engraved with abstract designs have been found at the site of the Blombos Cave in South Africa, dated to around 75,000 years ago. In Wales, the paleolithic burial called the Red Lady of Paviland from its coating of red ochre has been dated to around 33,000 years before present. Paintings of animals made with red and yellow ochre pigments have been found in sites at Pech Merle in France. The cave of Lascaux has an image of a horse colored with yellow estimated to be 17,300 years old. In Ancient Egypt, yellow was associated with gold, which was considered to be eternal, the skin and bones of the gods were believed to be made of gold.
The Egyptians used yellow extensively in tomb painting, though occasionally they used orpiment