This is the methodology behind every colour atlas we publish — not invented for one species and forgotten, but the same three-axis framework, the same honesty about screen limits, and the same insistence on checking our own work against independent labs, applied consistently every time.
A lab certificate names one point in a three-dimensional space. Naming only one axis and leaving the other two silent is how "vivid" turns into a marketing word instead of a coordinate.
The dominant colour family, named with a modifier when it isn't pure — "orangy red," "purplish pink." The modifier always comes first, the base hue last.
How light or dark the colour reads, independent of intensity. Two stones can share identical saturation and look nothing alike if their tone differs.
How intense or dull the colour is — the axis independent labs actually grade on a scale from weak to vivid. This is what "vivid" measures, precisely.
We borrow real trade vocabulary wherever it already exists, and we're explicit whenever we've had to build a term ourselves to fill a genuine gap.
Gemologists already call a light-toned stone "open" when internal light-play shows through the facets, and an overly dark one "closed." GRS's own scale separately uses "vivid to deep" as a real transitional grade. We pair the two explicitly — same saturation, different tone, named consistently across every atlas we publish.
Every atlas we publish carries the same honest line: pixels are a guide, not a guarantee. No display renders colour identically, and we'd rather say that plainly than let a screen's quirks be mistaken for the actual grade.
Every saturation strip and colour comparison in a Lithós atlas is built from actual photographed, and where possible certified, stones — not synthetic gradients standing in for reality.
Wherever we can, we check our own colour placement against an independent lab's published methodology — Bellerophon Gemlab's numeric HSB system, GIA and GRS terminology, Lotus Gemology's published research — and we name exactly which source backs which claim.
When we editorialize — a locality we personally trust more, a cut style we favour — it's marked as our take, separate from the measured facts around it. Never blended into one undifferentiated voice.
If a fact changes or we get something wrong, the fix is dated and logged, not quietly erased. A living reference should show its work.
The first full application of this standard — real certified stones, lab-verified saturation grading, and independent cross-checks throughout.
More species-specific atlases, built on this same standard, are in progress.