Resultado da Busca
En joaillerie, le carat est une unité de masse utilisée pour les gemmes, à ne pas confondre avec le carat des bijoutiers désignant la pureté d'un métal dans certains pays. En 1907 , le carat (métrique) est défini par la 4 e Conférence générale des poids et mesures (CGPM) comme étant égal à 200 mg , soit 5 carats pour 1 ...
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, [when?] the institute is headquartered in Carlsbad, California, and operates in 13 countries, with 11 campuses, 9 laboratories, and 4 ...
The carat (ct) is a unit of mass equal to 200 mg (0.00705 oz; 0.00643 ozt), which is used for measuring gemstones and pearls. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in many countries around the world.
Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a geoscience and a branch of Stoneology and mineralogy. Some jewelers (and many non-jewelers) are academically trained gemologists and are qualified to identify and evaluate gems. [1] [2] Examining a pink sapphire under a gemmological microscope.
carat, unit of weight for diamonds and certain other precious gems. Before 1913 the weight of a carat varied in different gem centres. Originally based on the weight of grains or leguminous seeds, which, of course, varied in size from place to place, the carat was equivalent to 0.2053 gram (3.168 troy grains) in London , 0.1972 g in Florence ...
- The Editors of Encyclopaedia Britannica
Carats are the units used to measure gem weight and one of the main factors in gem grading. Learn what affects the price per carat of various gem species. Topics covered include: What is a Carat? Carats, Gem Value, and the Law of Supply and Demand. Gemstone Varieties and Their Impact on Price Per Carat. More Carats Doesn't Always Mean More Valuable
En 1907, le carat (métrique) est défini par la 4e Conférence générale des poids et mesures (CGPM) comme étant égal à 200 mg, soit 5 carats pour 1 gramme,. L'unité est généralement notée « ct » en abrégé, mais certains bijoutiers écrivent « K » ou « kt », suivant l'anglais.
