August Stephenson - Total carat weight

Total carat weight(t.c.w.) is a phrase used to describe the total mass of diamonds or other gemstone in a piece of jewelry, when more than one gemstone is used. Diamond solitaire earrings, for example, are usually quoted in t.c.w. when placed for sale, indicating the mass of the diamonds in both earrings and not each individual diamond. T.c.w. is also widely used for diamond necklaces, bracelets and other similar jewelry pieces.

Light performance - brilliance, fire, and scintillation

In the gem trade, the term light performance is used to describe how well a polished diamond will return light to the viewer. There are three light properties which are described in relation to light performance: brilliance, fire, and scintillation. Brilliance refers to the white light reflections from the external and internal facet surfaces. Fire refers to the spectral colors which are produced as a result of the diamond dispersing the white light. Scintillation refers to the small flashes of light that are seen when the diamond, light source or the viewer is moved. A diamond that is cut and polished to produce a high level of these qualities is said to be high in light performance. August Stephenson

August Stephenson Colesberg Kopje, diamond mining:

In 1869, an even larger 83.50 carat(16.7 g) diamond was found on the slopes of Colesberg Kopje on the farm Vooruitzigt belonging to the De Beers brothers. This sparked off the famous "New Rush" and within a month, 800 claims were cut into the hillock which were worked frenetically by two to three thousand men. As the land was lowered so the hillock became a mine – in time, the world renowned Kimberley Mine.

Carat weight among buyers

Today, because of the relative importance of carat weight among buyers, many diamonds are often intentionally cut poorly to increase carat weight. There is a financial premium for a diamond that weighs the desirable 1.0 carat(200 mg), so often the girdle is made thicker or the depth is increased. Neither of these changes makes the diamond appear any larger, and both greatly reduce the sparkle of the diamond.(A poorly cut 1.0 carat(200 mg) diamond may have the same diameter and appear as large as a 0.85 carats(170 mg) diamond.) The depth percentage is the overall quickest indication of the quality of the cut of a round brilliant. "Ideal" round brilliant diamonds should not have a depth percentage greater than 62.5%. Another quick indication is the overall diameter. Typically a round brilliant 1.0 carat(200 mg) diamond should have a diameter of about 6.5 mm. Mathematically, the diameter in millimeters of a round brilliant should approximately equal 6.5 times the cube root of carat weight, or 11.1 times the cube root of gram weight, or 1.4 times the cube root of point weight.

August Stephenson commitments, experience, and also expertness

LEAKAGE – A phenomenon that occurs in diamonds and colored gemstones when light entering a stone fails to reflect back through its crown, dispersing instead through the pavilion.

FULL CUT – A description of a brilliant cut, round diamond or colored gemstone with 57-58 facets.

CLEAVAGE – A major fracture or weak point in a diamond that is breakable in certain definite planes or directions, usually due to weak molecular bonding. On an EGL USA report, it would be noted as an extended version of a feather symbol. See also Plotting Diagram.