Masterclasses

Coloured Diamonds

A considered NOBILITH introduction to coloured diamonds: colour, character, documentation and individual selection.

A single faceted coloured diamond on a dark background

At NOBILITH, coloured diamonds are introduced as complete gemstones rather than as a single visual impression. A coloured diamond displays a noticeable body colour that contributes directly to its identity and appeal. Yellow, pink, blue, green, orange, brown and other colours may occur naturally or through treatment.

Chapters

Introduction

Formation

Every coloured diamond carries a history of formation, growth and change. Natural colour can result from trace elements, lattice defects, irradiation-related processes or geological deformation. The cause of colour is not always visible and requires professional examination.

Mineralogy and chemistry

Its mineral identity provides the foundation, while the individual stone gives that foundation its character. The material remains diamond, but minute structural and chemical differences alter light absorption. Spectroscopy is often important for understanding colour origin.

Colour

Colour is often the first thing we notice, but it is the balance of the whole stone that holds the eye. Fancy-colour assessment considers hue, tone, saturation and distribution. Face-up appearance, colour strength, modifying hues and cut interact strongly.

Origins

Locality can add context to a gemstone, but it belongs to the evidence of the individual stone and not to assumption. The visual colour does not establish geographic origin. Provenance and mine-of-origin claims require separate evidence and transparent chain of custody.

Inclusions

The interior of a gemstone is part of its story and should be read with curiosity and restraint. Clarity characteristics may be more or less visible depending on colour strength. They remain relevant to identity, durability, transparency and value.

Gem Lab

Coloured diamond microscope study

Use magnification to compare colour zoning and internal structure without reducing the stone to one feature.

Illustration: microscope view of a coloured diamond with colour zoning

Choose a lens

Swipe or choose a lens

Microscope images: illustrations of typical features, not a laboratory finding.

10×

Colour zoning

Colour may be distributed unevenly through a diamond. The visible pattern is described together with the overall colour assessment.

Treatments

Treatment belongs in the dossier because it shapes how a gemstone should be understood, cared for and described. Irradiation, annealing, high-pressure high-temperature processing and surface coating can create or modify colour. Reports must state treatment clearly, and care instructions must follow the treatment.

Cut and proportions

Cut is where material becomes presence: it controls how the gemstone meets light and how it feels when viewed. Cutting may concentrate or distribute colour. Shape, symmetry, face-up distribution and light performance are judged together with the intended colour effect.

Quality characteristics

A serious assessment looks for balance rather than a single headline characteristic. Colour strength, hue, distribution, clarity, cut, size, treatment and documentation are all material. Rarity claims require evidence and careful wording.

Laboratory examination

Laboratory work is strongest when several observations are brought together and interpreted in context. Laboratories combine spectroscopy, microscopy and other methods to identify colour origin and treatment where possible. Conclusions may include limitations.

Origin determination

An origin opinion is valuable precisely because it is evidence-led and allowed to remain inconclusive when necessary. Colour origin and geographic origin are separate questions. Neither should be implied by a marketing description.

Understanding the report

A report becomes useful when it is read as one part of the gemstone's wider identity and dossier. Check whether the report addresses natural or treated colour, the colour description, treatment status, grading terminology and verification number.

History and significance

The cultural story of a gemstone can enrich ownership while remaining separate from its examination record. Coloured diamonds have become symbols of individuality and rarity. Their personal meaning should remain distinct from unsupported investment claims.

NOBILITH Selection

NOBILITH selection begins with the complete picture and ends with a clear reason for choosing the individual gemstone. NOBILITH presents coloured diamonds with precise colour language, explicit treatment disclosure, verified reports and a clear distinction between fact and interpretation.

Updated 2026-09-30