COLOUR INTENSITY SCALE

Faint

Only the faintest trace of colour, often appearing pastel or near-colourless, with a soft and delicate look.

Pale

Soft, pastel hues with low saturation and tone; colours appear delicate and almost washed out.

Light

Noticeable but gentle colour, brighter than pale, yet still soft and airy in appearance.

Medium Light

Clear and lively colour that is stronger than light but not yet intense; retains brightness and openness.

Medium Intense

Displays balanced saturation with rich colour tones that remain bright and lively without appearing dark.

Vivid

Maximum saturation without heaviness; colours appear bright, pure, and strikingly intense.

Deep

Strong and dark in tone, producing rich, dramatic hues though with reduced brightness.

Dark

Very strong tone where colour appears heavy or inky, vibrancy is reduced and brilliance often masked.

Note: Industry trade names such as “pigeon blood” ruby or “cornflower blue” sapphire fall within these categories, but are not shown separately here. A stone-specific guide to help place these follows below.

LUSTRE/BRILLIANCE SCALE

Top

Exceptional shine and bright reflections, showing strong light return and a crisp sparkle.

Medium

Noticeable brightness but with softer reflections and a more subtle overall glow.

Low

Soft and muted appearance, often near-opaque looking with minimal internal light.

CLARITY SCALE

Eye Clean

No visible inclusions to the naked eye.

Visible Inclusions

Minor inclusions can be seen without magnification but don’t significantly affect beauty.

Included

Obvious inclusions visible to the eye, often affecting brilliance.

CUT QUALITY SCALE

Excellent

Precise and symmetrical with well-defined facets and a clean, polished finish.

Good

Generally well-cut with fair symmetry and proportions, may show soft facet definition.

Poor

Irregular or uneven cut with softened edges or visible imperfections.