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Glossary
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- Ideal Cut or American Cut
- Those proportions and facet angles calculated mathematically by Marcel Tolkowsky to produce maximum brilliancy consistent with a high degree of fire in a round diamond brilliant are considered by many diamond men to constitute the ideal cut. These figures, computed as a percentage of the girdle diameter, are as follows: total depth, 59.3% (without provision for girdle thickness); crown depth, 16.2%; pavilion depth, 43.1%. The bezel angle is 34° 30’ and the pavilion angle is 40° 45’. Girdle thickness as a percentage of the girdle’s diameter varies with size. The larger the stone, the smaller the percentage for a medium girdle. The variation is from about 1% to 3%.
- Imperfect
- The diamond imperfection grade at the low end of the “flawless-to-imperfect” (or “perfect-to-imperfect”) scale. An imperfect diamond contains imperfections that are visible face up to the unaided eye or that have a serious effect on the stone’s durability. The Gemological Institute of America recognizes two grades in the imperfect category.
- Imperfection
- A general term used to refer to any external blemish or internal inclusion or flaw on or in a fashioned diamond; e.g., a feather, carbon spot, knot, fissure, scratch, natural, etc. The term “flaw” and “imperfection” are usually used interchangeably.
- Inclusion
- A general term used to refer to any external blemish or internal inclusion or flaw on or in a fashioned diamond; e.g., a feather, carbon spot, knot, fissure, scratch, natural, etc. The term “flaw” and “imperfection” are usually used interchangeably.
- Intense Yellow
- This term is just as it sounds. When looking at a diamond of this grade you will see the vibrant yellow color from the face of the diamond. If you are purchasing a diamond of this grade insist on a certificate from either the GIA or HRD. Intense yellow is the middle grade in this category. The first is fancy yellow and the third is vivid yellow.
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