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Brian Gavin
Brian Gavin (born 14 November 1957) is a fifth-generation diamond cutter from South Africa. Referred to as "Brian the Cutter," Gavin is best known for establishing a quality benchmark and grading system for hearts and arrows diamonds, a specialized precision-cut form of the round Brilliant (diamond cut), brilliant diamond. Hearts and arrows grading system Renowned for strictness, Gavin's system for the grading of hearts and arrows diamonds was first presented at the 2004 International Diamond Cut Conference (IDCC) in Moscow Russia. Available free of charge, his system is in-use by credentialed diamond appraisers and consumer-protection laboratories. Family history Brian is the son of Ben Gavin (1929–2009), master diamond cutter, and Femma Gavin, a well known South African artist featured in the Smithsonian Libraries’ Collection (1935–2006). He is the grandson of Esther Alida (Stella) Aronson (1915–1980) and Barend Deutz (1911–1987) master diamond cutter from the well k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hearts And Arrows
Hearts and Arrows (H&A) diamonds are precision-cut variations of the traditional 57 faceted round Diamond cut#Round brilliant, brilliant cut. They are cut to Diamond cut#Proportions, "ideal" proportions with good optical symmetry, polish and a specific faceting pattern. When all these factors are present, the result is a repeatable, near perfect pattern of eight symmetrical arrows in the face-up position of the stone (called 'crown') and eight symmetrical hearts when viewed in the table-down position (called 'pavilion'). Design factors The original Hearts and Arrows were diamonds that surfaced in the mid 1980s in Japan that embodied three important design factors. The first of these factors was that they were cut to what is known in the diamond industry as "ideal proportions," i.e. very close to those summarized by Marcel Tolkowsky in his 1919 book, ''Diamond Design''. Second, they were cut with very good physical and optical symmetry so that they would garner the grade of "Excelle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brilliant (diamond Cut)
A brilliant is a diamond or other gemstone cut in a particular form with numerous facets so as to have exceptional brilliance. The shape resembles that of a cone and provides maximized light return through the top of the diamond. Even with modern techniques, the cutting and polishing of a diamond crystal always results in a dramatic loss of weight; rarely is it less than 50%. The round brilliant cut is preferred when the crystal is an octahedron, as often two stones may be cut from one such crystal. Oddly shaped crystals such as macles are more likely to be cut in a '' fancy cut''—that is, a cut other than the round brilliant—which the particular crystal shape lends itself to. Facet proportions and names The original round brilliant-cut was developed by Marcel Tolkowsky in 1919. The ideal proportions are 100% diameter, 53% table, 43.1% pavilion and 16.2% crown. The girdle and culet (if anynot part of Tolkowsky's original design) are cut from the ideal brilliant. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Diamond Cut Conference (IDCC)
International is an adjective (also used as a noun) meaning "between nations". International may also refer to: Music Albums * ''International'' (Kevin Michael album), 2011 * ''International'' (New Order album), 2002 * ''International'' (The Three Degrees album), 1975 *''International'', 2018 album by L'Algérino Songs * The Internationale, the left-wing anthem * "International" (Chase & Status song), 2014 * "International", by Adventures in Stereo from ''Monomania'', 2000 * "International", by Brass Construction from ''Renegades'', 1984 * "International", by Thomas Leer from ''The Scale of Ten'', 1985 * "International", by Kevin Michael from ''International'' (Kevin Michael album), 2011 * "International", by McGuinness Flint from ''McGuinness Flint'', 1970 * "International", by Orchestral Manoeuvres in the Dark from '' Dazzle Ships'', 1983 * "International (Serious)", by Estelle from '' All of Me'', 2012 Politics * Political international, any transnational organization of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appraiser
An appraiser (from Latin ''appretiare'', "to value"), is a person that develops an opinion of the market value or other value of a product, most notably real estate. The current definition of "appraiser" according to the Uniform Standards of Professional Appraisal Practice (USPAP) is: "One who is expected to perform valuation services competently and in a manner that is independent, impartial and objective." USPAP further comments on this definition: "Such expectation occurs when individuals, either by choice or by requirement placed upon them or upon the service they provide by law, regulation, or agreement with the client or intended users, represent that they comply." To be a real property appraiser in the United States, an individual must be licensed as an appraiser by the state in which they practice. This real property appraisal license is based on a background investigation, an understanding of USPAP and compliance of all associated state laws and regulations. Apprai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laboratories
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicians' offices, clinics, hospitals, and regional and national referral centers. Overview The organisation and contents of laboratories are determined by the differing requirements of the specialists working within. A physics laboratory might contain a particle accelerator or vacuum chamber, while a metallurgy laboratory could have apparatus for casting or refining metals or for testing their strength. A chemist or biologist might use a wet laboratory, while a psychologist's laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as those commonly used by computer scientists, computers (sometimes supercomputers) are used for either simulations or the analysis of data. Scienti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the Capital of the Netherlands, capital and Municipalities of the Netherlands, most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the City Region of Amsterdam, urban area and 2,480,394 in the Amsterdam metropolitan area, metropolitan area. Located in the Provinces of the Netherlands, Dutch province of North Holland, Amsterdam is colloquially referred to as the "Venice of the North", for its large number of canals, now designated a World Heritage Site, UNESCO World Heritage Site. Amsterdam was founded at the mouth of the Amstel River that was dammed to control flooding; the city's name derives from the Amstel dam. Originally a small fishing village in the late 12th century, Amsterdam became a major world port during the Dutch Golden Age of the 17th century, when the Netherlands was an economic powerhouse. Amsterdam is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannesburg
Johannesburg ( , , ; Zulu and xh, eGoli ), colloquially known as Jozi, Joburg, or "The City of Gold", is the largest city in South Africa, classified as a megacity, and is one of the 100 largest urban areas in the world. According to Demographia, the Johannesburg–Pretoria urban area (combined because of strong transport links that make commuting feasible) is the 26th-largest in the world in terms of population, with 14,167,000 inhabitants. It is the provincial capital and largest city of Gauteng, which is the wealthiest province in South Africa. Johannesburg is the seat of the Constitutional Court, the highest court in South Africa. Most of the major South African companies and banks have their head offices in Johannesburg. The city is located in the mineral-rich Witwatersrand range of hills and is the centre of large-scale gold and diamond trade. The city was established in 1886 following the discovery of gold on what had been a farm. Due to the extremely large gold de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DeBeers
De Beers Group is an international corporation that specializes in diamond mining, diamond exploitation, diamond retail, diamond trading and industrial diamond manufacturing sectors. The company is active in open-pit, large-scale alluvial and coastal mining. It operates in 35 countries and mining takes place in Botswana, Namibia, South Africa, Canada and Australia. From its inception in 1888 until the start of the 21st century, De Beers controlled 80% to 85% of rough diamond distribution and was considered a monopoly. Competition has since dismantled the complete monopoly; the De Beers Group now sells approximately 29.5% of the world's rough diamond production by value through its global sightholder and auction sales businesses. The company was founded in 1888 by British businessman Cecil Rhodes, who was financed by the South African diamond magnate Alfred Beit and the London-based N M Rothschild & Sons bank. In 1926, Ernest Oppenheimer, a German immigrant to Britain and later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sightholder
A sightholder is a company on the De Beers Global Sightholder Sales's (DBGSS) list of authorized bulk purchasers of rough diamonds. De Beers Group made this list, the second largest miner of diamonds. DBGSS was previously known as DTC (Diamond Trading Company). In May 2006, DTC released a list of the 93 sightholders on its website. The DTC Sightholder list was further reduced to 79 companies worldwide in December 2007. The list of selected companies for the 2008-2011 contract period was published in April 2008. The DTC list of sightholders for 2021 is as follows; *A. Dalumi Diamonds *Almod Diamonds Ltd. *AMC NV *Ankit Gems Private Limited *Arjav Diamonds NV *Asian Star Company Limited *Chow Sang Sang Jewellery Company Limited *Chow Tai Fook Jewellery Co.Ltd. *Dali Diamond Co. *Dharmanandan Diamonds Pvt Ltd *Diacor International Ltd. *Dianco *Diarough NV *Dimexon International Holding BV *Finestar Jewellery & Diamonds Pvt. Ltd. * Hari Krishna Exports Pvt. Ltd. *Hasenfeld-Stein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Cutting
Diamond cutting is the practice of shaping a diamond from a rough stone into a faceted gem. Cutting diamonds requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty. The first guild of diamond cutters and polishers (Diamantaire) was formed in 1375 in Nuremberg, Germany, and led to the development of various types of "cut". This has two meanings in relation to diamonds. The first is the shape: square, oval, and so on. The second relates to the specific quality of cut within the shape, and the quality and price will vary greatly based on the cut quality. Since diamonds are one of the hardest materials, special diamond-coated surfaces are used to grind the diamond down. The first major development in diamond cutting came with the "Point Cut" during the later half of the 14th century: the Point Cut follows the natural shape of an octahedral rough diamond crystal, eliminating some waste in the cutting process. Diamond cutting, as well as overa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1957 Births
1957 ( MCMLVII) was a common year starting on Tuesday of the Gregorian calendar, the 1957th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 957th year of the 2nd millennium, the 57th year of the 20th century, and the 8th year of the 1950s decade. Events January * January 1 – The Saarland joins West Germany. * January 3 – Hamilton Watch Company introduces the first electric watch. * January 5 – South African player Russell Endean becomes the first batsman to be dismissed for having ''handled the ball'', in Test cricket. * January 9 – British Prime Minister Anthony Eden resigns. * January 10 – Harold Macmillan becomes Prime Minister of the United Kingdom. * January 11 – The African Convention is founded in Dakar. * January 14 – Kripalu Maharaj is named fifth Jagadguru (world teacher), after giving seven days of speeches before 500 Hindu scholars. * January 15 – The film ''Throne of Blood'', Akira Kurosawa's reworking of '' Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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