N is a diamond colour grade on the GIA D-to-Z scale, marking the top of the 'very light' colour-tint range that runs from N through R. At grade N a face-up diamond shows noticeable yellow or brown tint to a trained eye under controlled lighting, though the tint is still relatively faint and many casual observers will not perceive it strongly when the stone is mounted in jewellery, especially when set in yellow gold.

Position on the scale

The GIA scale runs from D (colourless) through Z (light yellow or brown), grouped as colourless (D-F), near colourless (G-J), faint (K-M), very light (N-R), and light (S-Z). N sits below the popular near-colourless range and the prices fall accordingly: N-grade stones routinely trade at sharp discounts to F, G, and H goods of the same clarity, cut, and weight. The exact discount depends on size — larger stones with higher colour grades tend to gap more aggressively from N material than smaller stones do.

Grading practice

Grading is done by comparison to a set of master stones representing each grade, viewed table-down through the pavilion under standardised daylight-equivalent lighting. The decision points between adjacent grades are subtle, and trained graders work multiple times across a stone before assigning a grade. GIA reports use letter grades for stones graded loose; mounted stones receive grade ranges (e.g., 'M-N') because mounted grading is less precise than loose-stone grading.

Use

N-colour diamonds appear primarily in commercial and mid-market jewellery where colour is less critical to value than carat weight. They are commonly set in yellow gold, which masks the yellow tint by visual continuity with the metal. White-metal settings — platinum or white gold — make the tint more apparent and are generally avoided for N-colour material in fine retail. See also O, P, Q, R colour grades.

Further reading

• GIA — diamond colour reference
• GIA Gems & Gemology — colour grading articles