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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] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard conditions for temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) color diamond blue (bor ... [...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] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...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] |
Symmetry
Symmetry (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definition, and is usually used to refer to an object that is invariant under some transformations; including translation, reflection, rotation or scaling. Although these two meanings of "symmetry" can sometimes be told apart, they are intricately related, and hence are discussed together in this article. Mathematical symmetry may be observed with respect to the passage of time; as a spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including theoretic models, language, and music. This article describes symmetry from three perspectives: in mathematics, including geometry, the most familiar type of symmetry for many people; in science and nature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
America
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-American ... [...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 and 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. Today, the institute is headquartered in Carlsbad, California and operates in 13 countries, with 11 campuses, 9 laboratories and 4 research centers. History The story of the GIA begins in the 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Gemological Institute
International Gemological Institute (IGI) is a diamond, colored stone and jewelry certification organization. IGI is headquartered in Antwerp and has offices in New York City, Hong Kong, Mumbai, Bangkok, Tokyo, Dubai, Tel Aviv, Toronto, Los Angeles, Kolkata, New Delhi, Surat, Chennai, Thrissur, Ahmedabad, Shanghai, and Cavalese. Established in 1975, IGI is the largest independent gemological laboratory worldwide. It also runs Schools of Gemology in several locations around the globe. Operations IGI has a staff of over 650 gemologists, appraisers and professional office personnel. The International Gemological Institute "has been at the forefront of technology since its commencement in 1975". This characteristic can be seen in the actions that the IGI has taken recently towards creating an Online Data Retrieval program and its Registration and Recovery Service. The IGI is also perfecting methods to reliably distinguish between synthetic and natural diamonds. IGI provides its se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sales
Sales are activities related to selling or the number of goods sold in a given targeted time period. The delivery of a service for a cost is also considered a sale. The seller, or the provider of the goods or services, completes a sale in response to an acquisition, appropriation, requisition, or a direct interaction with the ''buyer'' at the point of sale. There is a passing of title (property or ownership) of the item, and the settlement of a price, in which agreement is reached on a price for which transfer of ownership of the item will occur. The ''seller'', not the purchaser, typically executes the sale and it may be completed prior to the obligation of payment. In the case of indirect interaction, a person who sells goods or service on behalf of the owner is known as a salesman or saleswoman or salesperson, but this often refers to someone selling goods in a store/shop, in which case other terms are also common, including '' salesclerk'', ''shop assistant'', and ''r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marketing
Marketing is the process of exploring, creating, and delivering value to meet the needs of a target market in terms of goods and services; potentially including selection of a target audience; selection of certain attributes or themes to emphasize in advertising; operation of advertising campaigns; attendance at trade shows and public events; design of products and packaging attractive to buyers; defining the terms of sale, such as price, discounts, warranty, and return policy; product placement in media or with people believed to influence the buying habits of others; agreements with retailers, wholesale distributors, or resellers; and attempts to create awareness of, loyalty to, and positive feelings about a brand. Marketing is typically done by the seller, typically a retailer or manufacturer. Sometimes tasks are contracted to a dedicated marketing firm or advertising agency. More rarely, a trade association or government agency (such as the Agricultural Marketing Servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Standard
A technical standard is an established norm or requirement for a repeatable technical task which is applied to a common and repeated use of rules, conditions, guidelines or characteristics for products or related processes and production methods, and related management systems practices. A technical standard includes definition of terms; classification of components; delineation of procedures; specification of dimensions, materials, performance, designs, or operations; measurement of quality and quantity in describing materials, processes, products, systems, services, or practices; test methods and sampling procedures; or descriptions of fit and measurements of size or strength. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes, and practices. In contrast, a custom, convention, company product, corporate standard, and so forth that becomes generally accepted and dominant is often called a ''de facto'' standard. A techni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Gem Society
The American Gem Society (AGS) is a trade association of retail jewelers, independent appraisers, suppliers, and selective industry members, which was founded in 1934 by Robert M. Shipley. The Society is based in Las Vegas, Nevada, along with the affiliated American Gem Society Laboratories (AGSL) (founded in 1996) and the American Gem Society Advanced Instruments Division (founded in 2004). The Society trains and certifies jewelers, gemologists, and jewelry appraisers. Diamond grading is a specialty of the American Gem Society Laboratories and the Society has developed its own cut, color, and clarity Clarity may refer to: Arts, entertainment, and media Fictional entities * Clarity, a magic spell in the online game ''EverQuest'' * Clarity, a fictional drug from the film '' Minority Report'' Music Albums * ''Clarity'' (Jimmy Eat World album) ... standards. History The AGS was created by Robert M. Shipley. During the 1920s, Shipley was operating quite successfully as a jewe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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