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Diamond Proportions
Table, depth, crown and pavilion — the numbers behind light performance.
Proportions describe the relationships between a diamond's parts. They are recorded on the grading report as percentages of the average girdle diameter.
Table percentage
The table is the large flat facet on top. A table that is too large reduces fire; too small reduces brilliance. Ranges of roughly 53–58% suit round brilliants, while step cuts commonly run higher.
Depth percentage
Depth is the measurement from table to culet relative to width. Excessive depth hides weight beneath the girdle and reduces face-up size; shallow depth can create a dark centre.
Read the numbers alongside the video
Proportions are indicators, not verdicts. Stones outside textbook ranges can be beautiful, and stones inside them can underperform. Always look at the diamond.
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Diamond Shapes
How each outline behaves in the light, which proportions matter, and how shape influences perceived size.
The 4Cs
Carat, colour, clarity and cut — what each grade actually measures and where it matters most.
Diamond Certification
Why an independent grading report matters and how to read one with confidence.