Quartz is the second most abundant mineral in Earths continental crust, behind feldspar. There are many different varieties of quartz, several of which are semi-precious gemstones, since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. The word quartz is derived from the German word Quarz and its Middle High German ancestor twarc, the Ancient Greeks referred to quartz as κρύσταλλος derived from the Ancient Greek κρύος meaning icy cold, because some philosophers apparently believed the mineral to be a form of supercooled ice. Today, the rock crystal is sometimes used as an alternative name for the purest form of quartz. Quartz belongs to the crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end, well-formed crystals typically form in a bed that has unconstrained growth into a void, usually the crystals are attached at the other end to a matrix and only one termination pyramid is present.
However, doubly terminated crystals do occur where they develop freely without attachment, a quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. α-quartz crystallizes in the crystal system, space group P3121 and P3221 respectively. β-quartz belongs to the system, space group P6222 and P6422. These space groups are truly chiral, both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks. The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is an identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent, common colored varieties include citrine, rose quartz, smoky quartz, milky quartz, and others.
The most important distinction between types of quartz is that of macrocrystalline and the microcrystalline or cryptocrystalline varieties, the cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate, carnelian or sard, heliotrope, amethyst is a form of quartz that ranges from a bright to dark or dull purple color. The worlds largest deposits of amethysts can be found in Brazil, Uruguay, France, sometimes amethyst and citrine are found growing in the same crystal. It is referred to as ametrine, an amethyst is formed when there is iron in the area where it was formed
Middle Stone Age
The Middle Stone Age was a period of African prehistory between the Early Stone Age and the Later Stone Age. It is generally considered to have begun around 280,000 years ago, the beginnings of particular MSA stone tools have their origins as far back as 550–500,000 years ago and as such some researchers consider this to be the beginnings of the MSA. The MSA is associated with anatomically modern humans as well as archaic Homo sapiens, sometimes referred to as Homo helmei. Early physical evidence comes from the Gademotta Formation in Ethiopia, the Kapthurin Formation in Kenya and it is difficult to discuss the MSA of Africa without first considering the immense size of the continent. Preservation in these two regions are alternately superb and lamentable, yet the sites that have been uncovered document the adaptive nature of early hominins to climatically unstable environments. Eastern Africa represents some of the most reliable dates, due to the use of radiocarbon dating on volcanic ash deposits, faunal preservation, however, is not spectacular, and standardization in site excavation and lithic classification was, until recently, lacking.
Central Africa reflects similar patterning to eastern Africa, yet more archaeological research of the region is certainly required, southern Africa consists of many cave sites, most of which show very punctuated starts and stops in stone tool technology. Research in southern Africa has been continuous and quite standardized, allowing for reliable comparisons between sites in the region. Much of the evidence for the origins of modern human behavior is traced back to sites in this region, including Blombos Cave, Howiesons Poort, Still Bay. The origins of the MSA are characterized in most regions by the Acheulian to MSA transition and this transition is considered to be a gradual process, rather than a singular event wherein hominin technologies advanced rapidly. Although the dates for this vary widely, the oldest reliably dated MSA site is Gademotta in Ethiopia at greater than 276 thousand years ago. The Middle Awash valley of Ethiopia and the Central Rift Valley of Kenya constituted a major center for behavioural innovation and this suggests a possible overlap of 100-150 thousand years.
The Cave of Hearths and Montague Cave in South Africa contain evidence of Acheulian technologies, as well as MSA technologies, Early blades have been documented as far back as 550-500,000 years in the Kapthurin Formation in Kenya and Kathu Pan in South Africa. Backed pieces from the Twin Rivers and Kalambo Falls sites in Zambia, a high level of technical competence is indicated for the c.280 ka blades recovered from the Kapthurin Formation, Kenya. The stone tool technology in use during the Middle Stone Age shows a mosaic of techniques, the use of blades is seen at many sites as well. In Africa, blades may have used during the transition from the Early Stone Age to the Middle Stone Age onwards. Artifact technology during the Middle Stone Age shows a pattern of innovation followed by disappearance and this occurs with technology such as the manufacture of shell beads and hide working tools including needles, and gluing technology. These pieces of evidence provide a counterpoint to the classic Out of Africa scenario in which increasing complexity accumulated during the Middle Stone Age, perhaps only in small numbers initially, but by 30 ka they had replaced Neanderthals and H. erectus
Ensete ventricosum, commonly known as the Ethiopian banana, Abyssinian banana, false banana, enset or ensete, is an herbaceous species of flowering plant in the banana family Musaceae. The name Ensete ventricosum was first published in 1948 in the Kew Bulletin,1947 and its synonyms include Musa arnoldiana De Wild. Musa ventricosa Welw. and Musa ensete J. F. Gmel, like bananas, Ensete ventricosum is a large non-woody plant — a gigantic monocarpic evergreen perennial herb — up to 6 m tall. It has a stout pseudostem of tightly overlapping leaf bases, and large banana-like leaf blades of up to 5 m tall by 1 m wide, with a salmon-pink midrib. The flowers, which occur once from the centre of the plant at the end of that plants life, are in massive pendant thyrses covered by large pink bracts. The fruits are inedible and have hard, rounded seeds, Enset provides more amount of foodstuff per unit area than most cereals. It is estimated that 40 to 60 enset plants occupying 250-375 sq. meters can provide food for a family of 5 to 6 people.
– Country Information Brief, FAO June 1995, Enset is Ethiopias most important root crop, a traditional staple in the densely populated south and southwestern parts of Ethiopia. Its importance to the diet and economy of the Gurage and Sidama peoples was first recorded by Jerónimo Lobo, the root is the main edible portion as its fruit is insipid. Each plant takes four to five years to mature, at time a single root will give 40 kg of food. Due to the period of time from planting to harvest, plantings need to be staggered over time. Enset will tolerate drought better than most cereal crops, Wild enset plants are produced from seeds, while most domesticated plants are propagated from suckers. Up to 400 suckers can be produced from just one mother plant, in 19943,000 km² of enset were grown in Ethiopia, with a harvest estimated to be almost 10 tonnes per hectare. Enset is often intercropped with sorghum, although the practice amongst the Gedeo is to intercrop it with coffee and it is a major crop, although often supplemented with cereal crops.
Hence farmers were overexploiting their Enset reserves thereby causing gradual losses, the young and tender tissues in the centre or heart of the plant are cooked and eaten, being tasty and nutritious and very like the core of palms and cycads. In Ethiopia, more than 150000 ha are cultivated for the starchy staple food prepared from the pulverised trunk, fermenting these pulverised parts results in a food called kocho. Bulla is made from the liquid squeezed out of the mixture and sometimes eaten as a porridge, mixed kocho and bulla can be kneaded into dough and baked over a fire. Kocho is in places regarded as a delicacy, suitable for serving at feasts and ceremonies such as weddings, the fresh corm is cooked like potatoes before eating
Absolute dating is the process of determining an age on a specified chronology in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating, as use of the word implies a unwarranted certainty of accuracy. Absolute dating provides an age or range in contrast with relative dating which places events in order without any measure of the age between events. Techniques include tree rings in timbers, radiocarbon dating of wood or bones, radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes. Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material, one of the most widely used and well-known absolute dating techniques is carbon-14 dating, which is used to date organic remains. This is a technique since it is based on radioactive decay. Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide, carbon-14 moves up the food chain as animals eat plants and as predators eat other animals.
With death, the uptake of carbon-14 stops and it takes 5,730 years for half the carbon-14 to change to nitrogen, this is the half-life of carbon-14. After another 5,730 years only one-quarter of the original carbon-14 will remain, after yet another 5,730 years only one-eighth will be left. By measuring the carbon-14 in organic material, scientists can determine the date of death of the matter in an artifact or ecofact. The relatively short half-life of carbon-14,5,730 years, an additional problem with carbon-14 dates from archeological sites is known as the old wood problem. Thus dating that particular tree does not necessarily indicate when the fire burned or the structure was built, for this reason, many archaeologists prefer to use samples from short-lived plants for radiocarbon dating. The development of mass spectrometry dating, which allows a date to be obtained from a very small sample, has been very useful in this regard. Other radiometric dating techniques are available for earlier periods, one of the most widely used is potassium-argon dating.
Potassium-40 is an isotope of potassium that decays into argon-40. The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, potassium is common in rocks and minerals, allowing many samples of geochronological or archeological interest to be dated. Argon, a gas, is not commonly incorporated into such samples except when produced in situ through radioactive decay. The date measured reveals the last time that the object was heated past the closure temperature at which the trapped argon can escape the lattice, k-Ar dating was used to calibrate the geomagnetic polarity time scale
Hypoxis hemerocallidea, the African star grass or African potato, is a medicinal plant in the Hypoxidaceae family. It is native to southern Africa from South Africa as far north as Mozambique and this plant is the best known member of this genus. Limited evidence from two clinical trials suggests that Hypoxis appears to some symptoms secondary to benign prostatic hyperplasia. Additionally, Hypoxis alters the activity of cytochrome p450, suggesting that it may interfere with the effectiveness of drugs or supplements
Armenia, officially the Republic of Armenia, is a sovereign state in the South Caucasus region of Eurasia. The Republic of Armenia constitutes only one-tenth of historical Armenia, Armenia is a unitary, multi-party, democratic nation-state with an ancient cultural heritage. Urartu was established in 860 BC and by the 6th century BC it was replaced by the Satrapy of Armenia, in the 1st century BC the Kingdom of Armenia reached its height under Tigranes the Great. Armenia became the first state in the world to adopt Christianity as its official religion, in between the late 3rd century to early years of the 4th century, the state became the first Christian nation. The official date of adoption of Christianity is 301 AD. The ancient Armenian kingdom was split between the Byzantine and Sasanian Empires around the early 5th century, under the Bagratuni dynasty, the Bagratid Kingdom of Armenia was restored in the 9th century. Declining due to the wars against the Byzantines, the fell in 1045. An Armenian principality and a kingdom Cilician Armenia was located on the coast of the Mediterranean Sea between the 11th and 14th centuries.
By the 19th century, Eastern Armenia had been conquered by the Russian Empire, during World War I, Armenians living in their ancestral lands in the Ottoman Empire were systematically exterminated in the Armenian Genocide. By 1920, the state was incorporated into the Transcaucasian Socialist Federative Soviet Republic, in 1936, the Transcaucasian state was dissolved, transforming its constituent states, including the Armenian Soviet Socialist Republic, into full Union republics. The modern Republic of Armenia became independent in 1991 during the dissolution of the Soviet Union, the Republic of Armenia recognises the Armenian Apostolic Church, the worlds oldest national church, as the countrys primary religious establishment. The unique Armenian alphabet was invented by Mesrop Mashtots in 405 AD, Armenia is a member of the Eurasian Economic Union, the Council of Europe and the Collective Security Treaty Organization. Armenia supports the de facto independent Nagorno-Karabakh Republic, which was proclaimed in 1991, the native Armenian name for the country is Հայք.
The name in the Middle Ages was extended to Հայաստան, by addition of the Persian suffix -stan, the further origin of the name is uncertain. It is postulated that the name Hay comes from one of the two confederated, Hittite vassal states—the Ḫayaša-Azzi. The exonym Armenia is attested in the Old Persian Behistun Inscription as Armina, the ancient Greek terms Ἀρμενία and Ἀρμένιοι are first mentioned by Hecataeus of Miletus. Xenophon, a Greek general serving in some of the Persian expeditions, describes many aspects of Armenian village life and he relates that the people spoke a language that to his ear sounded like the language of the Persians. According to the histories of both Moses of Chorene and Michael Chamchian, Armenia derives from the name of Aram, a descendant of Hayk
A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric, archaeologists often study such prehistoric societies, and refer to the study of stone tools as lithic analysis. Ethnoarchaeology has been a research field in order to further the understanding and cultural implications of stone tool use. Stone has been used to make a variety of different tools throughout history, including arrow heads, spearpoints. Stone tools may be made of ground stone or chipped stone. Chipped stone tools are made from materials such as chert or flint, chalcedony, basalt. One simple form of reduction is to strike stone flakes from a nucleus of material using a hammerstone or similar hard hammer fabricator, if the goal of the reduction strategy is to produce flakes, the remnant lithic core may be discarded once it has become too small to use. In some strategies, however, a flintknapper reduces the core to a rough unifacial or bifacial preform, more complex forms of reduction include the production of highly standardized blades, which can be fashioned into a variety of tools such as scrapers, knives and microliths.
Archaeologists classify stone tools into industries that share distinctive technological or morphological characteristics and he assigned to them relative dates, Modes 1 and 2 to the Lower Palaeolithic,3 to the Middle Palaeolithic,4 to the Advanced and 5 to the Mesolithic. They were not to be conceived, however, as either universal—that is, they did not account for all lithic technology, Mode 1, for example, was in use in Europe long after it had been replaced by Mode 2 in Africa. Clarkes scheme was adopted enthusiastically by the archaeological community, one of its advantages was the simplicity of terminology, for example, the Mode 1 / Mode 2 Transition. The transitions are currently of greatest interest, Kenya Stone tools found from 2011 to 2014 at Lake Turkana in Kenya, are dated to be 3.3 million years old, and predate the genus Homo by half million years. The oldest known Homo fossil is 2.8 million years old compared to the 3.3 million year old stone tools. Dating of the tools was by dating volcanic ash layers in which the tools were found, Oldowan tools were characterised by their simple construction, predominantly using core forms.
The blunt end is the surface, the sharp, the distal. Grasping the proximal surface, the hominid brought the surface down hard on an object he wished to detach or shatter. The earliest known Oldowan tools yet found date from 2.6 million years ago, during the Lower Palaeolithic period, and have been uncovered at Gona in Ethiopia. Homo habilis was the hominin who used the tools for most of the Oldowan in Africa, more complex, Mode 2 tools began to be developed through the Acheulean Industry, named after the site of Saint-Acheul in France
Rhyolite is an igneous, volcanic rock, of felsic composition. It may have any texture from glassy to aphanitic to porphyritic, the mineral assemblage is usually quartz and plagioclase. Biotite and hornblende are common accessory minerals and it is the extrusive equivalent to granite. Rhyolite can be considered as the equivalent to the plutonic granite rock. Due to their content of silica and low iron and magnesium contents, rhyolite melts are highly polymerized. They occur as breccias or in volcanic plugs and dikes, rhyolites that cool too quickly to grow crystals form a natural glass or vitrophyre, called obsidian. Slower cooling forms microscopic crystals in the lava and results in such as flow foliations, nodular. Some rhyolite is highly vesicular pumice, many eruptions of rhyolite are highly explosive and the deposits may consist of fallout tephra/tuff or of ignimbrites. Eruptions of rhyolite are relatively rare compared to eruptions of less felsic lavas, etsch Valley Vulcanite Group near Bolzano and the surrounding area Gréixer rhyolitic complex at Moixeró range Vosges Iceland, all active and extinct central volcanoes, e. g. g.
Wichita Mountains within the Southern Oklahoma Aulacogen St, in North American pre-historic times, rhyolite was quarried extensively in eastern Pennsylvania in the United States. Among the leading quarries was the Carbaugh Run Rhyolite Quarry Site in Adams County, comendite List of rock types Pantellerite Thunderegg University of North Dakota description of rhyolite Information from rocks-rock. com
Niassa is a province of Mozambique. It has an area of 122,827 km2 and a population of 1,027,037 and it is the most sparsely populated province in the country. Lichinga is the capital of the province, there are a minimum estimated 450,000 Yao people living in Mozambique. They largely occupy the eastern and northern part of the Niassa province and form about 40% of the population of Lichinga, the Ruvuma River forms much of the northern boundary of the province with Tanzania while Lake Niassa forms the western border of the province, separating it from Malawi. 75% of the province remains untouched by development, and remains free of landmines, the province shares the Niassa National Reserve with neighboring Cabo Delgado Province. In 1998, a college was built in Lichinga to train teachers. Partially financed by the Irish Embassy in Maputo, it graduates 60 teachers a year, apart from training teachers for local schools, the college offers primary school education to the local Lichinga community and works towards reducing the impact of HIV/AIDS in Niassa province
The Tischofer Cave is a cave in the Kaisertal valley in the Kaisergebirge mountains in Austria. It was important locally as a place and weapons cache for local rebels during the Napoleonic Wars. The roughly 40 m long cave, which is about 8.5 m high at the entrance, was used during the Stone Age by bears and other predators as shelter and that makes the Tischofer Cave the oldest proven site of human occupation in Tyrol. Discoveries of human skeletons and tools indicate that the cave acted as a copper smithy, the Tischofer Cave may be reached on foot via the Kaiser Path in the Kaisertal valley, a pathway secured with cable railings. It is recorded in the Tyrolean Cave Register as number 1312/001, article from Hofmann, Wege im Inntal with comprehensive description Die Tischofer Höhle im Kaisertal bei Kufstein at www. tirol-infos. at. Tischofer Höhle im Kaisertal at www. kaisergebirge-online. de
It is separated from Madagascar by the Mozambique Channel to the east. The capital and largest city is Maputo, between the 1st and 5th centuries AD, Bantu-speaking peoples migrated from farther north and west. Swahili commercial ports existed along the coasts until the arrival of Europeans, the area was explored by Vasco da Gama in 1498 and colonised by Portugal from 1505. The country was an important place where Somali merchants enslaved the local population, after over four centuries of Portuguese rule, Mozambique gained independence in 1975, becoming the Peoples Republic of Mozambique shortly thereafter. After only two years of independence, the country descended into an intense and protracted civil war lasting from 1977 to 1992, in 1994, Mozambique held its first multiparty elections and has remained a relatively stable presidential republic. However, since 2013, following more than 20 years of peace, Mozambique is one of the poorest and most underdeveloped countries in the world. Mozambique is endowed with rich and extensive natural resources, the countrys economy is based largely on agriculture, but industry is growing, mainly food and beverages, chemical manufacturing, and aluminium and petroleum production.
The countrys tourism sector is growing, South Africa is Mozambiques main trading partner and source of foreign direct investment. Belgium, Brazil and Spain are among the countrys most important economic partners, since 2001, Mozambiques annual average GDP growth has been among the worlds highest. However, the ranks among the lowest in GDP per capita, human development, measures of inequality. The only official language of Mozambique is Portuguese, which is mostly as a second language by about half of the population. Common native languages include Makhuwa and Swahili, the countrys population of around 24 million is composed overwhelmingly of Bantu people. The largest religion in Mozambique is Christianity, with significant minorities following Islam, the island-town was the capital of the Portuguese colony until 1898, when it was moved south to Lourenço Marques. Between the 1st and 5th centuries AD, waves of Bantu-speaking people migrated from the west and north through the Zambezi River valley and gradually into the plateau and they established agricultural communities or societies based on herding cattle.
They brought with them the technology for smelting and smithing iron, from the late first millennium AD, vast Indian Ocean trade networks extended as far south into Mozambique as the ancient port town of Chibuene. Connections are evident at sites including Manyikeni for 11–14th century ties with the inland Great Zimbabwe kingdoms, from about 1500, Portuguese trading posts and forts displaced the Arabic commercial and military hegemony, becoming regular ports of call on the new European sea route to the east. The voyage of Vasco da Gama around the Cape of Good Hope in 1498 marked the Portuguese entry into trade, the Portuguese attempted to legitimise and consolidate their trade and settlement positions through the creation of prazos tied to Portuguese settlement and administration. Historically within Mozambique there was slavery, Human beings were bought and sold by African tribal chiefs, Arab Muslim traders and Portuguese and other European traders as well
The Levallois technique is a name given by archaeologists to a distinctive type of stone knapping developed by precursors to modern humans during the Palaeolithic period. It is named after finds of flint tools in the Levallois-Perret suburb of Paris. The technique was more sophisticated than earlier methods of lithic reduction, a striking platform is formed at one end and the cores edges are trimmed by flaking off pieces around the outline of the intended lithic flake. This creates a shape on the side of the core, known as a tortoise core as the various scars. When the striking platform is finally hit, a lithic flake separates from the core with a distinctive plano-convex profile. Scientists consider the Levallois complex to be a Mode 3 technology and this is one level superior to the Acheulean complex of the Lower Paleolithic. The technique is first found in the Lower Palaeolithic but is most commonly associated with the Neanderthal Mousterian industries of the Middle Palaeolithic, in the Levant, Levallois methods were in use in the Upper Palaeolithic and later.
In East Africa, Levallois methods were used in the Middle Stone Age, while Levallois cores do display some variability in their planform, their flake production surfaces show remarkable uniformity. This would seem to indicate some sort of teaching process was occurring. The distinctive forms of the flakes were originally thought to indicate a wide ranging Levallois culture resulting from the expansion of archaic Homo sapiens out of Africa, the wide geographical and temporal spread of the technique has rendered this interpretation obsolete. Aside from technique, the commonality in Levallois complexes is the attention given to maximizing core efficiency. A recent article by Lycett and Eren statistically shows the efficiency of the Levallois technique which at times has been called into question and Eren created 75 Levallois flakes from 25 Texas Chert nodules. They counted the 3957 flakes and separated them into four stages in order to show efficiency, the experiment shows that the Levallois core is an economic optimal strategy of raw material usage, which mean it can generate longest cutting edge per weight unit of raw material.
There is disagreement when it comes to defining Levallois technology, archeologists question which attributes and dimensions are specifically associated with Levallois, and argue that there are other techniques with similar cosmetic and functional aspects. Due to these disagreements, there is now a more set of criteria that outlines Levallois technology from a geometric standpoint. Egypt, Within the banks of the Nile River, excavations have located within the 30-, 15-, within the 30-foot terrace, the implements were originally thought to be early Mousterian, but were reclassified. The 15- and 10-foot terraces again were classified first as Egyptian Mousterian, Large Levallois flakes struck from boulder cores have been found at the Kapthurin Formation site in western Kenya, near Lake Bogoria and Lake Baringo. The earliest examples come from the Leaky Handaxe Area and the Factory Site, both examples feature large flakes, approximately 10–20 cm in diameter, and have been dated between 284 and 509 thousand years ago