Saturation 4 — Moderately Strong on the GIA Scale
Saturation 4 — Moderately Strong on the GIA Scale
The lower boundary of premium coloured-stone colour, with negligible neutral masking
Saturation 4 is the middle-upper grade on GIA's six-point saturation scale, indicating moderately strong colour with clear chroma and negligible grey or brown masking. Stones graded saturation 4 exhibit good colour purity and are widely used in fine jewellery: this grade represents the lower boundary of premium material in many species, sitting below the strong (5) and vivid (6) grades that command top prices but distinctly above the commercial-tier saturations.
In the trade
Saturation 4 in fine sapphire produces a clean, recognisably blue colour with no visible grey shadow; in ruby, a clear red without brown undertone; in emerald, a properly green stone without yellow or grey shift. The grade is the practical floor for what the trade calls fine quality in most species and the level at which retail prices begin to reflect colour as the primary value driver. A stone with saturation 4, well-cut and free from significant clarity faults, will command meaningful premium over saturation-3 material of the same hue and tone.
Where the price step lies
The market price step from saturation 4 to saturation 5 is large in fine ruby, sapphire, and emerald, often exceeding the step from saturation 3 to 4 by a multiple. The reason is supply: saturation-4 material is found across many sources and across many quality bands, while saturation-5 and saturation-6 stones are concentrated in particular hue and tone combinations from a small number of producing regions. Saturation 4 is the upper edge of broadly available fine material; above it, supply tightens and pricing reflects scarcity. See also saturation, saturation 1, saturation 2, saturation 3, saturation 5, saturation 6.