The Cut
Brilliance is a decision, not an accident.
Color and clarity are graded by nature. Cut is the one variable a human controls — and the one that decides whether a stone comes alive.
A short history
The round brilliant is a math problem, solved in 1919.
Marcel Tolkowsky, a young engineer from a family of diamond cutters, calculated the angles that return the most light through the crown of a round stone. A century later, our cutters still work from proportions descended from his formula — adjusted, stone by stone, for the particular way each rough bends light.
Facet geometry
Fifty-seven facets, each placed to a fraction of a degree.
A standard round brilliant carries 33 facets on the crown (including the table) and 24 on the pavilion below the girdle — 57 in total, sometimes 58 with a culet facet. Cut a fraction too deep or too shallow and light leaks out the bottom instead of bouncing back to your eye.
Weight vs. light
A heavier stone is not always a brighter one.
Cutters are paid, historically, by the carat retained — which tempts a deep, heavy cut that hides weight below the girdle where it can't be seen or admired. We cut for face-up brilliance first and let the final weight fall where the light says it should.
Fire, in motion
One ray in. Three colors out.
White light enters the crown, reflects internally off two pavilion facets, and exits split into color — the same dispersion a prism shows, compressed into a single stone.