MSU Diamond Cut Study

"Мicroanalysis" The pavilion angle ranged from 38° to 43°, the crown angle - from 30° to 40°. In different grading systems, the existing cut classes look like rectangular parallelepipeds.

Figure 4

The light return coefficient nLR_30 for a diamond with the table size Dp=53%. The illumination: diffused (a source of diffused daylight of the "Office" type).

Within these parallelepipeds described in the grading systems, such as AGS, the light return and fire coefficients considerably vary. For example, some parameter sets belonging to group 3 may yield better light return and fire than some sets from group 0. This is true for all the existing cut grading systems that define the cut parameter groups as the rectangular parallelepipeds embedded in one another (see Fig.4-6). [Details]

Figure 5

The fire coefficient nMF_30 for a diamond with the table size Dp=53%.

Figure 6

The fire coefficient nMF_30 for a diamond with the table size Dp=60%.

photo-realistic images of diamonds have cut parameters on the cut grade AGS 2 borderline. The left image is diamond with minimum and the right image is diamond with maximum light return for all cut grade AGS 2. The light sources model "Office" illumination conditions.

A = 32.2° B = 40.9° Dp=53% Gd=2.6%	A = 32.2° B = 41.3° Dp=53% Gd=2.6%	A = 36.8° B = 40.25° Dp=53% Gd=2.7%	A = 36.8° B = 41.86° Dp=53% Gd=2.8%
nLR_30=1.05 nMF_30=1.00	nLR_30=1.02 nMF_30=0.98	nLR_30=0.97 nMF_30=1.00	nLR_30=0.86 nMF_30=1.0

photo-realistic images of the same diamonds but illumination conditions model those actually used for taking photographs of diamonds (a few lateral sources of diffused light).

A = 32.2° B = 40.9° Dp=53% Gd=2.6%	A = 32.2° B = 41.3° Dp=53% Gd=2.6%	A = 36.8° B = 40.25° Dp=53% Gd=2.7%	A = 36.8° B = 41.86° Dp=53% Gd=2.8%
Q=1.05 EFF=1.07	Q=1.00 EFF=0.98	Q=0.97 EFF=0.97	Q=0.86 EFF=0.79