The Details of Diamond Proportions
Ideal Proportions
Nature is responsible for the colour and the clarity of a diamond. The cut, that aspect that unlocks a diamond's hidden beauty, is the skill and craft of a talented diamond cutter.
Lacking an accepted industry wide standard for cut grading, as there are for clarity and colour, HWL has developed a scale of cut grading as described below. In general terms this is what it means:
Excellent Cut (HW Grade 1 to 1+)
Diamonds cut to "ideal" proportions, as shown in the diagram. This cutting
yields a diamond of maximum brilliance and beauty. A stone cut to these proportions will
be considerably more expensive than a diamond of the same clarity and colour but of poorer
cut.
Good Cut (HW Grade 2 to 3)
Diamonds cut just outside the tolerances of the ideal cut.
Average Cut (HW Grade 4)
Diamonds cut to average proportions, with somewhat reduced brilliance and beauty to
trained observer.
Commercial Cut (HW Grade 5 to 6)
Diamonds cut with reduced brilliance to the untrained eye, or significant
retention of weight from the rough.
Irregular Cut (HW Grade 7 to 8)
Diamonds cut with distinctly reduced brilliance to the untrained eye, or significant
retention of weight from the rough. Our appraisal is usually based on a hypothetical
recutting to more regular proportions.
Below you can see how we place an "ideal" cut stone on our scale and also a fairly average "deep" stone. In general given the same weight (carat) the stone on the left will comand a premium in price, and exhibit more fire and brilliance.
Diamonds 101 | Grading Scales | Ideal Proportions