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Gabi Tolkowsky
Gabriel S. "Gabi" Tolkowsky (born January 1, 1939) Clara Chow, ''Urban, The Straits Times'', 31 October 2008 known for cutting the famous , is one of the world's most renowned ters. Known as the father of the modern diamond cut. and the great nephew of |
Centenary Diamond
The De Beers Centenary Diamond is, at , the third-largest diamond to have been produced in the Premier Mine. Among top-color diamonds, only the Cullinan I and II are larger than the Centenary diamond. The Centenary Diamond is rated in color as grade D color by the Gemological Institute of America, which is the highest grade of colourless diamond and is internally and externally flawless. It was named the Centenary Diamond as it was presented in the rough for the Centennial Celebration of De Beers Consolidated Mines on 11 May 1988. The Centenary Diamond was unveiled in final form in May 1991. Discovery The Centenary Diamond was discovered in the Premier Mine on 17 July 1986 using their X-ray imaging system. The original rough was and it was presented on 11 May 1988 in the Centennial Celebration of the De Beers Consolidated Mines. As then-chairman Julian Ogilvie Thompson said, "We have recovered at the Premier Mine a diamond of which is perfect in colour – indeed it is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Cut
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut does not refer to shape (pear, oval), but the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance; this means if it is cut poorly, it will be less luminous. In order to best use a diamond gemstone's material properties, a number of different diamond cuts have been developed. A diamond cut constitutes a more or less symmetrical arrangement of facets, which together modify the shape and appearance of a diamond crystal. Diamond cutters must consider several factors, such as the shape and size of the crystal, when choosing a cut. The practical history of diamond cuts can be traced back to the Middle Ages, while their theoretical basis was not developed until the turn of the 20th century. Design, creation and innovation continue to the present day: new technology—notably laser cutting and computer-aided design— ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round Brilliant
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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcel Tolkowsky
Marcel Tolkowsky (25 December 1899 – 10 February 1991), Obituary. an engineer by education, was a Belgian member of a Jewish family of diamond cutters from Poland. He is generally acknowledged as the father of the modern round brilliant diamond cut. Many of his family have gone on to become noted diamond cutters, including his cousin Lazare Kaplan and his great-nephew Gabi Tolkowsky. Tolkowsky, as part of his PhD topic at the University of London, systematically studied the grinding of diamonds. Around the same time, in his book ''Diamond Design'', he published the specifications of what would later be called the ''American Standard'' (also known as the ''American Ideal Cut'', ''Tolkowsky cut'', and ''Tolkowsky Brilliant''), which is the diamond-cutting benchmark in North America. It was derived from mathematical calculations that considered both brilliance and fire of the stone. Marcel Tolkowsky found that if a diamond Diamond is a Allotropes of carbon, solid f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antwerp
Antwerp (; nl, Antwerpen ; french: Anvers ; es, Amberes) is the largest city in Belgium by area at and the capital of Antwerp Province in the Flemish Region. With a population of 520,504,Statistics Belgium; ''Loop van de bevolking per gemeente'' (Excel file) Population of all municipalities in Belgium, . Retrieved 1 November 2017. it is the most populous municipality in Belgium, and with a metropolitan population of around 1,200,000 people, it is the second-largest metrop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Beers
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] |
Golden Jubilee Diamond
The Golden Jubilee Diamond, a 545.67 carat (109.13 g) brown diamond, is the largest cut and faceted diamond in the world. It outweighs the Cullinan I by 15.37 carats (3.07 g). The Golden Jubilee Diamond was discovered in 1985 at the Premier Mine, which is also the origin of the Cullinan diamond (1905) and other notables such as the Taylor–Burton (1966) and the Centenary (1986). Cullinan I, also known as the Great Star of Africa, had held the title of the largest cut and faceted diamond since 1908. History First known as the "Unnamed Brown", the Golden Jubilee Diamond was cut from a large brown diamond of 755.5 carats (151 g), found in the prolific blue ground of the Premier Mine in South Africa in 1985. Until 1990, the diamond remained largely unknown to the outside world, requiring two years' work to bring it to its current state. A large surface and deep cracks from the interior, as well as several inclusions, meant that cutting and polishing the large diamond presente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Documentary Film
A documentary film or documentary is a non-fictional film, motion-picture intended to "document reality, primarily for the purposes of instruction, education or maintaining a Recorded history, historical record". Bill Nichols (film critic), Bill Nichols has characterized the documentary in terms of "a filmmaking practice, a cinematic tradition, and mode of audience reception [that remains] a practice without clear boundaries". Early documentary films, originally called "actuality films", lasted one minute or less. Over time, documentaries have evolved to become longer in length, and to include more categories. Some examples are Educational film, educational, observational and docufiction. Documentaries are very Informational listening, informative, and are often used within schools as a resource to teach various principles. Documentary filmmakers have a responsibility to be truthful to their vision of the world without intentionally misrepresenting a topic. Social media platfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgium
Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to the southwest, and the North Sea to the northwest. It covers an area of and has a population of more than 11.5 million, making it the 22nd most densely populated country in the world and the 6th most densely populated country in Europe, with a density of . Belgium is part of an area known as the Low Countries, historically a somewhat larger region than the Benelux group of states, as it also included parts of northern France. The capital and largest city is Brussels; other major cities are Antwerp, Ghent, Charleroi, Liège, Bruges, Namur, and Leuven. Belgium is a sovereign state and a federal constitutional monarchy with a parliamentary system. Its institutional organization is complex and is structured on both regional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1939 Births
This year also marks the start of the Second World War, the largest and deadliest conflict in human history. Events Below, the events of World War II have the "WWII" prefix. January * January 1 ** Third Reich *** Jews are forbidden to work with Germans. *** The Youth Protection Act was passed on April 30, 1938 and the Working Hours Regulations came into effect. *** The Jews name change decree has gone into effect. ** The rest of the world *** In Spain, it becomes a duty of all young women under 25 to complete compulsory work service for one year. *** First edition of the Vienna New Year's Concert. *** The company of technology and manufacturing scientific instruments Hewlett-Packard, was founded in a garage in Palo Alto, California, by William (Bill) Hewlett and David Packard. This garage is now considered the birthplace of Silicon Valley. *** Sydney, in Australia, records temperature of 45 ˚C, the highest record for the city. *** Philipp Etter took over as Swi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Related categories * :Year of birth missing (living people) / :Year of birth unknown * :Date of birth missing (living people) / :Date of birth unknown * :Place of birth missing (living people) / :Place of birth unknown * :Year of death missing / :Year of death unknown * :Date of death missing / :Date of death unknown * :Place of death missing / :Place of death unknown * :Missing middle or first names See also * :Dead people * :Template:L, which generates this category or death years, and birth year and sort keys. : {{DEFAULTSORT:Living people 21st-century people People by status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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