Cut Is King
Of the four Cs (cut, color, clarity, carat), cut has the single greatest impact on how beautiful a diamond looks. A perfectly cut diamond transforms white light into a dazzling display of brilliance (white light return), fire (rainbow flashes), and scintillation (sparkle pattern). A poorly cut diamond — regardless of color and clarity — looks lifeless. Cut is where you should never compromise.
What Cut Quality Means
Cut quality is NOT the shape of the diamond (round, oval, etc.). Cut quality measures how well a diamond's facets interact with light. It is determined by the precision of the diamond's proportions, symmetry, and polish. When a diamond is cut to ideal proportions, light enters through the top, bounces between the angled facets inside, and exits back through the top in a brilliant display. When proportions are off, light leaks out the bottom or sides, and the diamond appears dull.
Cut Grades (Round Brilliant)
- Excellent/Ideal: Maximum light performance. Proportions are optimized for brilliance and fire. Always choose this grade when available
- Very Good: Near-excellent light performance. Slight deviations from ideal proportions that are difficult to detect. A smart value choice if Excellent is over budget
- Good: Noticeable light performance reduction. Some light leaks through the bottom. Adequate but not impressive
- Fair: Significant light loss. The diamond appears noticeably less brilliant. Avoid for engagement rings
- Poor: Most light escapes. The diamond looks glassy or dark. Never recommended
Key Proportions
- Table percentage: The width of the top flat facet relative to the diamond's width. Ideal for round: 54-57%
- Depth percentage: The total height relative to the width. Ideal for round: 61-62.5%
- Crown angle: The angle of the top facets. Ideal: 34-35 degrees
- Pavilion angle: The angle of the bottom facets. Ideal: 40.6-41 degrees. This is the most critical measurement
Why Cut Matters More Than Size
A 1.50 carat diamond with Excellent cut will outperform a 2.00 carat diamond with Good cut in every way that matters — brightness, sparkle, fire, and visual beauty. The larger diamond may have more physical mass, but the smaller one will catch eyes from across the room while the larger one looks flat and lifeless.
Always Prioritize Cut
When budget is limited, always sacrifice color and clarity before cut. A 1.00 carat diamond with Excellent cut, H color, and SI1 clarity will look dramatically better than a 1.00 carat with Good cut, D color, and VVS1 clarity. The first diamond sparkles brilliantly. The second diamond is technically flawless but visually underwhelming.
