2009年4月7日星期二

Diamond cut

I had find many products about indian diamond jewelry from some websites such as


Silicone O-ring and Gasket

1. Product name: Silicone O ring and Gasket; 2. Made of 100% silicone; 3. OEM service, welcome your samples or drawings;

natural turquoise beads loose strands

variou sizes and quality available welcome try order favorite discount for bulk orders
And you can see more from cubic zirconia jewellery cubic zirconia pendant coin pearl beads copper light pendant crystal bead jewelry costume jewelry ring cultured saltwater pearls cultured pearl necklace clarity enhanced diamonds Part of the series on DiamondMaterialMaterial propertiesCrystallographic defectsFormation and surfacingThe 4 CsCarat ClarityColor CutProductionList of minesDiamond cuttingThe diamond industryDe BeersCultural impactHistory SymbolismFamous diamondsImitations and enhancementsSynthetics SimulantsEnhancementsSee alsoIndex of related articlesWikipedia Commons mediaA Diamond Cut is a style or design guide used when shaping a diamond for poilishing such as the Brilliant Cut. In order to best utilize 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姊無tably laser cutting and computer-aided design姊檃s enabled the development of cuts whose complexity, optical performance, and waste reduction were hitherto unthinkable.The most popular of diamond cuts is the modern round brilliant, whose facet arrangements and proportions have been perfected by both mathematical and empirical analysis. Also popular are the fancy cuts which come in a variety of shapes姊瀉ny of which were derived from the round brilliant. A diamond's cut is evaluated by trained graders, with higher grades given to stones whose symmetry and proportions most closely match the particular "ideal" used as a benchmark. The strictest standards are applied to the round brilliant; although its facet count is invariable, its proportions are not. Different countries base their cut grading on different ideals: one may speak of the American Standard or the Scandinavian Standard (Scan. D.N.), to give but two examples.Contents1 History 2 Theory 3 Polish and symmetry 4 Choice of cut 5 Round brilliant 5.1 Facet count and names 5.2 Proportions 5.3 Hearts and arrows phenomenon 6 Fancy cuts 6.1 Modified brilliants 6.2 Step cuts 6.3 Mixed cuts 6.4 Rose cuts 7 Cut grading 8 See also 9 References // HistoryDiagram of old diamond cuts showing their evolution from the most primitive (point cut) to the most advanced pre-Tolkowsky cut (old European). The rose cut is omitted, but it could be considered intermediate between the old single and Mazarin cuts.The history of diamond cuts can be traced to the late Middle Ages, before which time diamonds were enjoyed in their natural octahedral state姊恘hedral (poorly formed) diamonds simply were not used in jewelry. The first "improvements" on nature's design involved a simple polishing of the octahedral crystal faces to create even and unblemished facets, or to fashion the desired octahedral shape out of an otherwise unappealing piece of rough. This was called the point cut and dates from the mid 14th century; by 1375 there was a guild of diamond polishers at N榛祅berg. By the mid 15th century, the point cut began to be improved upon: a little less than one half of the octahedron would be sawn off, creating the table cut. The importance of a culet was also realised, and some table-cut stones may possess one. The addition of four corner facets created the old single cut (or old eight cut). Neither of these early cuts would reveal what diamond is prized for today; its strong dispersion or fire. At the time, diamond was valued chiefly for its adamantine lustre and superlative hardness; a table-cut diamond would appear black to the eye, as they do in paintings of the era. For this reason, colored gemstones such as ruby and sapphire were far more popular in jewelry of the era.In or around 1476, Lodewyk (Louis) van Berquem, a Flemish polisher of Bruges, introduced absolute symmetry in the disposition of facets. He cut stones in the shape known as pendeloque or briolette; these were pear-shaped with triangular facets on both sides. About the middle of the 16th century, the rose or rosette was introduced in Antwerp: it also consisted of triangular facets arranged in a symmetrical radiating pattern, but with the bottom of the stone left flat姊晄sentially a crown without a pavilion. Many large, famous Indian diamonds of old (such as the Orloff and Sancy) also feature a rose-like cut; there is some suggestion that Western cutters were influenced by Indian stones, because some of these diamonds may predate the Western adoption of the rose cut. However, Indian "rose cuts" were far less symmetrical as their cutters had the primary interest of...(and so on)


Red Coral Bead CS38

1. Material: BAMBOO CORAL 2. Type : JEWELRY SETS 3. Color: RED
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