A mineral is, broadly speaking, a solid chemical compound that occurs in pure form. A rock may consist of a single mineral, or may be an aggregate of two or more different minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are excluded, but some minerals are biogenic and/or are organic compounds in the sense of chemistry. Moreover, living beings synthesize inorganic minerals that occur in rocks. In geology and mineralogy, the term "mineral" is reserved for mineral species: crystalline compounds with a well-defined chemical composition and a specific crystal structure. Minerals without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound may occur with different crystal structures, each structure is considered different mineral species. Thus, for example and stishovite are two different minerals consisting of the same compound, silicon dioxide; the International Mineralogical Association is the world's premier standard body for the definition and nomenclature of mineral species.
As of November 2018, the IMA recognizes 5,413 official mineral species. Out of more than 5,500 proposed or traditional ones; the chemical composition of a named mineral species may vary somewhat by the inclusion of small amounts of impurities. Specific varieties of a species sometimes have official names of their own. For example, amethyst is a purple variety of the mineral species quartz; some mineral species can have variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group. Besides the essential chemical composition and crystal structure, the description of a mineral species includes its common physical properties such as habit, lustre, colour, tenacity, fracture, specific gravity, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid. Minerals are classified by key chemical constituents.
Silicate minerals comprise 90% of the Earth's crust. Other important mineral groups include the native elements, oxides, carbonates and phosphates. One definition of a mineral encompasses the following criteria: Formed by a natural process. Stable or metastable at room temperature. In the simplest sense, this means. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, water ice, solid only below 0 °C. Modern advances have included extensive study of liquid crystals, which extensively involve mineralogy. Represented by a chemical formula. Minerals are chemical compounds, as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution. For example, the olivine group is described by the variable formula 2SiO4, a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula. Mineral species themselves could have a variable composition, such as the sulfide mackinawite, 9S8, a ferrous sulfide, but has a significant nickel impurity, reflected in its formula.
Ordered atomic arrangement. This means crystalline. An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form and cleavage. There have been several recent proposals to classify amorphous substances as minerals; the formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound, crystalline and, formed as a result of geological processes." Abiogenic. Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced by biological processes without a geological component and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound the product can be accepted as a mineral."The first three general characteristics are less debated than the last two. Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes.
The organic class includes a rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names. According to these new r
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, physical properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. Early writing on mineralogy on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world and medieval China, Sanskrit texts from ancient India and the ancient Islamic World. Books on the subject included the Naturalis Historia of Pliny the Elder, which not only described many different minerals but explained many of their properties, Kitab al Jawahir by Persian scientist Al-Biruni; the German Renaissance specialist Georgius Agricola wrote works such as De re metallica and De Natura Fossilium which began the scientific approach to the subject. Systematic scientific studies of minerals and rocks developed in post-Renaissance Europe; the modern study of mineralogy was founded on the principles of crystallography and to the microscopic study of rock sections with the invention of the microscope in the 17th century.
Nicholas Steno first observed the law of constancy of interfacial angles in quartz crystals in 1669. This was generalized and established experimentally by Jean-Baptiste L. Romé de l'Islee in 1783. René Just Haüy, the "father of modern crystallography", showed that crystals are periodic and established that the orientations of crystal faces can be expressed in terms of rational numbers, as encoded in the Miller indices. In 1814, Jöns Jacob Berzelius introduced a classification of minerals based on their chemistry rather than their crystal structure. William Nicol developed the Nicol prism, which polarizes light, in 1827–1828 while studying fossilized wood. James D. Dana published his first edition of A System of Mineralogy in 1837, in a edition introduced a chemical classification, still the standard. X-ray diffraction was demonstrated by Max von Laue in 1912, developed into a tool for analyzing the crystal structure of minerals by the father/son team of William Henry Bragg and William Lawrence Bragg.
More driven by advances in experimental technique and available computational power, the latter of which has enabled accurate atomic-scale simulations of the behaviour of crystals, the science has branched out to consider more general problems in the fields of inorganic chemistry and solid-state physics. It, retains a focus on the crystal structures encountered in rock-forming minerals. In particular, the field has made great advances in the understanding of the relationship between the atomic-scale structure of minerals and their function. To this end, in their focus on the connection between atomic-scale phenomena and macroscopic properties, the mineral sciences display more of an overlap with materials science than any other discipline. An initial step in identifying a mineral is to examine its physical properties, many of which can be measured on a hand sample; these can be classified into density. Hardness is determined by comparison with other minerals. In the Mohs scale, a standard set of minerals are numbered in order of increasing hardness from 1 to 10.
A harder mineral will scratch a softer, so an unknown mineral can be placed in this scale by which minerals it scratches and which scratch it. A few minerals such as calcite and kyanite have a hardness that depends on direction. Hardness can be measured on an absolute scale using a sclerometer. Tenacity refers to the way a mineral behaves when it is broken, bent or torn. A mineral can be brittle, sectile, flexible or elastic. An important influence on tenacity is the type of chemical bond. Of the other measures of mechanical cohesion, cleavage is the tendency to break along certain crystallographic planes, it is described by the orientation of the plane in crystallographic nomenclature. Parting is the tendency to break along planes of weakness due to twinning or exsolution. Where these two kinds of break do not occur, fracture is a less orderly form that may be conchoidal, splintery, hackly, or uneven. If the mineral is well crystallized, it will have a distinctive crystal habit that reflects the crystal structure or internal arrangement of atoms.
It is affected by crystal defects and twinning. Many crystals are polymorphic, having more than
Royal College of Science
For the Irish college of the same name, see Royal College of Science. For its famous building, see Government Buildings; the Royal College of Science was a higher education institution located in South Kensington. Alumni include H. G. Wells and Brian May and are distinguishable by the letters ARCS after their name. Organisations linked with the college include the Royal College of Science Union and the Royal College of Science Association; the Royal College of Science has its earliest origins in the Royal College of Chemistry founded under the auspices of Prince Albert in 1845, located first in Hanover Square and from 1846 in somewhat cheaper premises in Oxford Street. Cash-strapped from the start as a private institution, in 1853 it was merged in with the School of Mines, founded in 1851 in Jermyn Street, placed under the newly created British government Science and Art Department, although it continued to retain its own premises and its own identity. In 1872-3 the College of Chemistry moved into a new building at South Kensington, along with the physics and biology classes taught at the School of Mines.
The building, built on land acquired for "educational purposes" by the commissioners of the Great Exhibition of 1851, next to another of Science and Art Department's projects the South Kensington Museum, had been intended to be a new school of naval architecture. But the scientists pressed the need for much better laboratory space, so the school of naval architecture instead went to Greenwich. One notable advocate for the new facilities was T. H. Huxley, who soon put them to good use, pioneering the expanded use of laboratory work in biology teaching; the Science and Art Department was keen to improve the quality of technical education, in particular the systematic training of school teachers, so new classes in mathematics, astronomy and agriculture were added, alongside the departments of mechanics and geology which soon moved from Jermyn Street.. In recognition of its broadened scope the "Metropolitan School of Science applied to Mining and the Arts", as it was known, was re-established in 1881 as the "Normal School of Science and Royal School of Mines", under Huxley as dean, the name being based on that of the École Normale in Paris.
The Normal School of Science, responsible for subjects including physics, mechanics and agriculture established its own identity, in 1890 the name Royal College of Science was granted by Royal Consent. The RCS and the Royal School of Mines subsequently merged in 1907 with the City and Guilds Central Technical College to form the Imperial College of Science and Technology, each continuing as a Constituent College of Imperial, which joined the University of London in 1929; this administrative structure continued until 2002, surviving Imperial's mergers with a number of medical schools, which were formed into a fourth constituent college. In 2002, Imperial abolished all the constituent colleges, including the Royal College of Science, in favour of a new faculty structure; the RCS was split into the Faculties of Life Sciences. However, in 2005 it was announced that the Faculties of Physical and Life Sciences would be re-merged to form the Faculty of Natural Sciences; this re-forms the original RCS structure, encompassing all the science departments of Imperial College.
Overall, it has amounted to no more than a name change from RCS to Faculty of Natural Sciences, the new faculty students' union has resurrected the name "Royal College of Science Union". In the years following the establishment of the Normal School of Science in 1881, space became pressing as the college expanded, so work began in 1900 on new premises. In 1906 the RCS moved into an imposing new building designed by Sir Aston Webb, built in a Classical style and had distinctive brick courses, it ran the length of the road today called Imperial College Road and faced the Imperial Institute. The RCS building featured state of the art chemistry and physics laboratories in the east and west wings with the library of the Science Museum located in the central section between them; the building has now been demolished, the western wing in 1961 to make way for a new biochemistry building, the central section in the mid-1970s. F. H. W. Sheppard, Imperial College, Survey of London: volume 38: South Kensington Museums Area, pp. 233–247.
Harold Allan, Physics in South Kensington Bill Griffith, Chemistry at Imperial College: the first 150 years Hannah Gay, East end, west end: Science education and class in mid-Victorian London, Canadian Journal of History, Aug 1997 Hannah Gay, The History of Imperial College London, 1907–2007, World Scientific, 2007 Lists of Royal College of Science students
National Library of Australia
The National Library of Australia is the largest reference library in Australia, responsible under the terms of the National Library Act for "maintaining and developing a national collection of library material, including a comprehensive collection of library material relating to Australia and the Australian people." In 2012–13, the National Library collection comprised 6,496,772 items, an additional 15,506 metres of manuscript material. It is located in Parkes, Canberra, ACT; the National Library of Australia, while formally established by the passage of the National Library Act 1960, had been functioning as a national library rather than a Parliamentary Library since its inception. In 1901, a Commonwealth Parliamentary Library was established to serve the newly formed Federal Parliament of Australia. From its inception the Commonwealth Parliamentary Library was driven to development of a national collection. In 1907 the Joint Parliamentary Library Committee under the Chairmanship of the Speaker, Sir Frederick William Holder defined the objective of the Commonwealth Parliamentary Library in the following words: The Library Committee is keeping before it the ideal of building up, for the time when Parliament shall be established in the Federal Capital, a great Public Library on the lines of the world-famed Library of Congress at Washington.
The present library building was opened on 15 August 1968 by Prime Minister John Gorton. The building was designed by the architectural firm of Bunning and Madden in the Late Twentieth Century Stripped Classical style; the foyer is decorated in marble, with stained-glass windows by Leonard French and three tapestries by Mathieu Matégot. The building was listed on the Australian Commonwealth Heritage List on 22 June 2004. In 2012–13 the Library collection comprised 6,496,772 items, with an estimated additional 2,325,900 items held in the manuscripts collection; the Library's collections of Australiana have developed into the nation's single most important resource of materials recording the Australian cultural heritage. Australian writers and illustrators are sought and well represented—whether published in Australia or overseas; the Library's collection includes all formats of material, from books, journals and manuscripts to pictures, maps, oral history recordings, manuscript papers and ephemera.
92.1% of the Library's collection has been catalogued and is discoverable through the online catalogue. The Library has digitized over 174,000 items from its collection and, where possible, delivers these directly across the Internet; the Library is a world leader in digital preservation techniques, maintains an Internet-accessible archive of selected Australian websites called the Pandora Archive. The Library collects material produced by Australians, for Australians or about the Australian experience in all formats—not just printed works—books, newspapers, posters and printed ephemera—but online publications and unpublished material such as manuscripts and oral histories. A core Australiana collection is that of John A. Ferguson; the Library has particular collection strengths in the performing arts, including dance. The Library's considerable collections of general overseas and rare book materials, as well as world-class Asian and Pacific collections which augment the Australiana collections.
The print collections are further supported by extensive microform holdings. The Library maintains the National Reserve Braille Collection; the Library houses the largest and most developing research resource on Asia in Australia, the largest Asian language collections in the Southern hemisphere, with over half a million volumes in the collection, as well as extensive online and electronic resources. The Library collects resources about all Asian countries in Western languages extensively, resources in the following Asian languages: Burmese, Persian, Japanese, Korean, Manchu, Thai and Vietnamese; the Library has acquired a number of important Western and Asian language scholarly collections from researchers and bibliophiles. These collections include: Australian Buddhist Library Collection Braga Collection Claasz Collection Coedes Collection London Missionary Society Collection Luce Collection McLaren-Human Collection Otley Beyer Collection Sakakibara Collection Sang Ye Collection Simon Collection Harold S. Williams Collection The Asian Collections are searchable via the National Library's catalogue.
The National Library holds an extensive collection of manuscripts. The manuscript collection contains about 26 million separate items, covering in excess of 10,492 meters of shelf space; the collection relates predominantly to Australia, but there are important holdings relating to Papua New Guinea, New Zealand and the Pacific. The collection holds a number of European and Asian manuscript collections or single items have been received as part of formed book collections; the Australian manuscript collections date from the period of maritime exploration and settlement in the 18th century until the present, with the greatest area of strength dating from the 1890s onwards. The collection includes a large number of outstanding single items, such as the 14th century Chertsey Cartulary, the journal of James Cook on the HM Bark Endeavour, inscribed on t
The Malvern Hills are a range of hills in the English counties of Worcestershire, Herefordshire and a small area of northern Gloucestershire, dominating the surrounding countryside and the towns and villages of the district of Malvern. The highest summit of the hills affords a panorama of the Severn Valley with the hills of Herefordshire and the Welsh mountains, parts of thirteen counties, the Bristol Channel, the cathedrals of Worcester and Hereford, they are known for their spring water – made famous by the region's many holy wells, through the development of the 19th-century spa town of Great Malvern, a process which culminated in the production of the modern bottled drinking water. The Malvern Hills have been designated as a biological and geological Site of Special Scientific Interest and as National Character Area 103 by Natural England and an Area of Outstanding Natural Beauty by the Countryside Agency; the SSSI notification has 26 units of assessment which cover grassland and geological sites.
The site is listed in the'Forest of Dean Local Plan Review' as a Key Wildlife Site. Management of the hills is the responsibility of the Malvern Hills Trust. Simon Jenkins rates the view of the Wye Valley and across the Severn Vale to the Cotswolds as one of the top ten in England; the name Malvern is derived from the ancient British moel-bryn, meaning "Bare-Hill", the nearest modern equivalent being the Welsh moelfryn. It has been known as Malferna and Much Malvern. Jabez Allies, a 19th-century antiquarian from Worcestershire speculated that'vern' was derived from the British words'Sarn' or'Varn' meaning pavement or seat of judgement; the Malvern Hills are part of an Area of Outstanding Natural Beauty, with scenic views over both Herefordshire and Worcestershire. The Hills run north/south for about 8 mi, in between Great Malvern and the village of Colwall, overlook the River Severn valley to the east, with the Cotswolds beyond; the highest point of the hills is the Worcestershire Beacon at 425 metres above sea level.
The hills are famous for their natural mineral springs and wells, which were responsible for the development of Great Malvern as a spa in the early 19th century. Until Malvern water was bottled commercially on a large scale and sold worldwide. There are three passes over the hills, the Wyche cutting, the A438 road north of Raggedstone Hill and the A449 road just north of the Herefordshire Beacon, the site of the British Camp, an Iron Age hill fort at the top of the hill; the site is thought to date back before the Common Era and has been extended subsequently by a medieval castle. The extensive earthworks remain visible today and determine the shape of the hill; the Malvern Hills are formed of some of the most ancient rocks in England igneous and metamorphic rocks from the late Precambrian, known as the Uriconian, which are around 680 million years old. The Malvern Line or Malvern Lineament is the name applied to a north-south aligned lineament which runs through the Malvern Hills and extends southwards towards Bristol and northwards past Kidderminster.
It consists of a series of faults and folds which have the effect of bringing old Malvernian rocks to the surface. Being hard igneous rocks, they have resisted erosion better than those of the surrounding countryside and result in a striking line of hills of which the Malvern Hills are the most impressive; this line is considered to mark the edge of two terranes – two once separate fragments of the Earth's crust now joined as one – the Wrekin Terrane to the west and the Charnwood Terrane to the east. The main face of Gullet Quarry shows a cross-section through the Precambrian rock and exhibits many rock types including diorite, gneiss, schist and dolerite; the evidence of the complex history of earth movements which formed the Hills can be seen by multiple joints, fractures and shears, which make identifying changes in rock types difficult. Mineral deposits such as haematite and epidote can be seen within these features. There is a man-made cave near the ridge of the hills called Clutter's Cave.
The cave has been excavated into pillow lavas. Some of the rounded'pillow' shapes are still visible around the entrance to the cave; the quality of Malvern water is attributable to its source. The rocks of the Malvern Hills are amongst the hardest found in England; the hills consist of Precambrian igneous and metamorphic rock, the oldest of which are about 670 million years old. The rocks are characterised by high secondary permeability via fissures. Malvern water is rainwater and snow meltwater that percolates through fissures created by the pressures of tectonic movements about 300 million years ago when advancing sedimentary layers of Silurian shale and limestone were pushed into and under older Precambrian rock; when the fissures are saturated, a water table forms and the water emerges as springs around the fault lines between the strata. Depending on rainfall, the flow can vary from as little as 36 litres per minute to over 350 litres per minute; the water permeates through the rock which, because of its hardness, leaves little or no mineral traces in the water, while at the same time the fine cracks act as a filter for other impurities.
Rainfall on the Malvern Hills is thought to be sufficient to account for all the water that r
Système universitaire de documentation
The système universitaire de documentation or SUDOC is a system used by the libraries of French universities and higher education establishments to identify and manage the documents in their possession. The catalog, which contains more than 10 million references, allows students and researcher to search for bibliographical and location information in over 3,400 documentation centers, it is maintained by the Bibliographic Agency for Higher Education. Official website