Diamond Guide
Cut is the most important of the 4 C's. It decides how well a diamond reflects light back to your eye, giving it fire, brilliance and scintillation.
The depth and proportions of the cut determine how a diamond reflects light, and whether it sparkles or falls flat.
Too Shallow
Light escapes the bottom
Ideal
Light returns to your eye
Too Deep
Light escapes the side
A diamond is only as brilliant as the light it sends back
Maximum brilliance. Reflects nearly all the light that enters the stone.
Reflects most of the light. Close to excellent, and noticeably better value.
Significant sparkle at a cost effective price, with some light loss.
A decent amount of reflection, but visibly duller beside a better cut.
Light escapes through the sides or bottom. We advise against these.
Cut is the only one of the 4 C's created entirely by human hands. Colour, clarity and carat are decided in the ground. Cut is decided at the bench.
Cut too shallow and light passes straight through the bottom of the stone. Cut too deep and it leaks out the sides. Only within a narrow band of proportions does light bounce internally and return through the table to your eye.
Cut also carries three sub-grades: Polish, Symmetry and Proportions. Look for Excellent or Very Good across all three.
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