What Does “Cut” Mean?
Diamond cut does not refer to shape (round, oval, cushion etc.) — it refers to how well a diamond's facets interact with light. A perfectly cut diamond reflects virtually all light back through the top (table), creating intense brilliance. A poorly cut stone lets light leak from the bottom or sides, appearing dull and lifeless.
The GIA Cut Scale
The Gemological Institute of America (GIA) grades cut on five levels for round brilliant diamonds:
- Ideal — Top 3% of all diamonds. Maximum brilliance, perfect proportions.
- Excellent — Reflects nearly all light. Visually indistinguishable from Ideal to most buyers.
- Very Good — Reflects most light. Outstanding value.
- Good — Reflects a significant amount of light. Suitable for those prioritising carat.
- Fair / Poor — Light escapes through the sides or bottom. Not recommended.
How Cut Affects Brilliance, Fire and Scintillation
Three optical properties make a diamond sparkle:
- Brilliance — White light reflecting back to your eye.
- Fire — Dispersion of light into spectral colours (the rainbow flashes).
- Scintillation — The sparkle pattern when the diamond or light source moves.
All three are maximised by excellent proportions: an ideal table percentage of 54–58%, depth percentage of 59–62.5%, and precise crown and pavilion angles. The GIA report lists all these measurements.
Avelyngold's Cut Policy
We stock only Excellent and Ideal cut round brilliants in our online catalogue. Every fancy-shape diamond (oval, cushion, pear, emerald) is manually reviewed by our in-house GIA-trained gemologists to ensure it meets our light-performance standards before being listed.
Cut vs. Carat: What to Prioritise?
If your budget is fixed, prioritise cut over carat. A 1.0 ct Excellent-cut diamond looks larger and brighter than a 1.2 ct Fair-cut stone — because more light returns to your eye. A well-cut smaller diamond will always outshine a larger poorly-cut one.