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Cut (gems)
A gemstone desired to be used in jewelry is cut, carved or made into a bead. The best quality rough is cut, also often referred to as faceting. This is done by a lapidary who decides how to reshape the gemstone using his knowledge of the refractive index of gemstones to maximise any particular crystal's colour or play of light. As a general rule, a cut gemstone will be reduced in mass (in carats) by about 50%. Among the several techniques used to work with gemstones are sawing, grinding, sanding, lapping, polishing, grilling, and tumbling. The diamond cut planning stage is a complex process that requires the cutter to work with unique rough stones. Very often, the location of the inclusions in a rough stone will determine the type of shape to which a diamond may be cut. For economic reasons, most diamonds are cut to retain weight instead of maximizing brilliance. How diamonds have been cut has evolved over time largely to technological advances. Types * Asscher cut * Bagu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Close-up Of Glass Crystal With Many Facets Causing Dispersion Spectrum From Light
A close-up or closeup in filmmaking, television production, still photography, and the comic strip medium is a type of shot that tightly frames a person or object. Close-ups are one of the standard shots used regularly with medium and long shots (cinematic techniques). Close-ups display the most detail, but they do not include the broader scene. Moving toward or away from a close-up is a common type of zooming. A close up is taken from head to neck, giving the viewer a detailed view of the subject's face. History Most early filmmakers, such as Thomas Edison, Auguste and Louis Lumière and Georges Méliès, tended not to use close-ups and preferred to frame their subjects in long shots, similar to the stage. Film historians disagree as to the filmmaker who first used a close-up. One of the best claims is for George Albert Smith in Hove, who used medium close-ups in films as early as 1898 and by 1900 was incorporating extreme close-ups in films such as ''As Seen Through a Te ... [...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 57-58 facets so as to have exceptional brilliance. The word 'brilliant' is also used for a diamond cut in this fashion. The underside is conical, a shape that provides maximal 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 this loss 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. Origin and etymology The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals. Around the 1500s, polishing and cutting inventions made it possible to shape diamond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemological Institute Of America
The Gemological Institute of America (GIA) is a nonprofit institute based in Carlsbad, California. It is dedicated to research and education in the field of gemology and the jewelry arts. Founded in 1931, GIA's mission is to protect buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality. The institute does so through research, gem identification, diamond grading services, and a variety of educational programs. Through its library and subject experts, GIA acts as a resource of gem and jewelry information for the trade, the public and media outlets. In 1953 the GIA developed its International Diamond Grading System and the "four Cs" ( cut, clarity, color, and carat weight) as a standard to compare and evaluate the quality of diamonds. As of 2024, the institute is headquartered in Carlsbad, California, and operates in 13 countries, with 11 campuses, 9 laboratories, and 4 research centers. History GIA was founded in the 1920s by ... [...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 (diamond cut), brilliant cut. Cut refers to shape (Pear cut, pear, oval), and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is less luminous. In order to best use a diamond gemstone's material properties of diamond, 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 cutting, 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. The earliest diamond cutting techniques were simply to polish the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Gemology And Jewelry/Lapidary
A WikiProject, or Wikiproject, is an affinity group for contributors with shared goals within the Wikimedia movement. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within sibling projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by '' Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outside organizations relevant to the field ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilliant Cut
A trilliant cut, sometimes called a trillion'', ''trillian, or Trielle is a triangular type of gemstone cut. The cut has many variations. It may have curved or uncurved sides. The shape of the top surface, or table, also varies. Stones typically have 31-50 facets. Creation The trilliant cut was introduced by the Asscher brothers in Amsterdam. In the early 1960s Leon Finker created his version on the "triangular brilliant cut diamond", which he called the trillion cut. Finker had a large diamond cutting factory in New York, and Henry Meyer Diamond Company, who was also cutting triangular brilliant diamonds, used the same diamond cutters, though their stones were cut slightly differently. Henry Meyer referred to his diamond cut as "trilliant", while Finker called his cut trillion. When Finker's son, Marvin Finker, entered the business in the early 1970s, he decided to patent the cut that his father was cutting and he trademarked the term "Trillion" for their now patented triangula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rose Cut
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut refers to shape (pear, oval), and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is 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. The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals; it wasn't until the 14 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiant Cut
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut refers to shape (pear, oval), and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is 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. The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals; it wasn't until the 14t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princess Cut
The princess cut (technical name 'square modified brilliant') is a diamond cut shape often used in engagement rings. The name dates back to the 1960s, while the princess cut as it exists was created by Betazel Ambar, Ygal Perlman, and Israel Itzkowitz in 1980. The cut has a square or rectangular shape when viewed from above, and from the side is similar to that of an inverted pyramid with four beveled sides. Its popularity was at its highest in the 80s and 90s, though its popularity was high in the 2000s as well. It is the second most popular diamond cut, below round and above cushion. Characteristics The face-up shape of the princess cut (technical name 'square modified brilliant' is square or rectangular and the profile or side-on shape is similar to that of an inverted pyramid with four beveled sides. The design is sometimes considered feminine. When looked down on, it bears an X shape. They are slightly less expensive and less cut than round diamonds. The sharp points of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pendeloque Cut
A pendeloque cut or pear cut, is a pear-shaped modification of the round brilliant cut used for diamonds and other gemstones. The pendeloque cut is sometimes erroneously called briolette cut, another drop-shaped cutting design. While the briolette is a symmetrical drop shape, the pendeloque cut is flatter and has two different sides: one with a large table facet and one with a point or ridge. The top of a briolette is attached to the piece of jewelry, usually by a hole drilled in the stone, and a pendeloque cut stone needs to be mounted in a prong setting. The pendeloque is one of the drop cuts for gemstones. The Smithsonian Institution has a diamond pendeloque and briolette necklace presented by Napoleon Bonaparte in 1811 to his Empress consort Marie Louise. See also * Briolette * Cut (gems) A gemstone desired to be used in jewelry is cut, carved or made into a bead. The best quality rough is cut, also often referred to as faceting. This is done by a lapidary who decides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emerald Cut
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut refers to shape (pear, oval), and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is 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. The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals; it wasn't until the 14 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
