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Colour guide · Ethiopian Paraiba

Ethiopian Paraiba Colours

Copper-bearing tourmaline spans a continuum from neon blue to light green. Where a stone sits depends on the balance of copper, manganese and iron, and on whether it has been heated.

By
Paraiba Ethiopia Editorial Team
Reviewed by
Review pending
Updated

What colour range occurs?

The trade describes five broad categories: neon blue, greenish blue, bluish green, vivid green and mint or light green. Saturation and brightness are as important as hue.

Colour categories used on this site
CategoryDescriptionNomenclature note
Neon BlueSaturated, bright blue with an electric qualityTypically within Paraíba criteria when copper-bearing
Greenish BlueBlue dominant with green secondary hueTypically within criteria
Bluish GreenGreen dominant with blue secondary hueTypically within criteria
Vivid GreenSaturated greenLaboratory-dependent
Mint / Light GreenLight tone, lower saturationMay fall outside criteria

What causes the different colours?

Copper (Cu²⁺) produces blue to green; manganese (Mn³⁺) adds pink to violet; iron can darken and push colour toward green. Heating can reduce Mn³⁺, removing violet tones and leaving a purer blue.

How should colour be judged?

Under neutral, daylight-equivalent lighting and face-up. Photographs and screens frequently exaggerate saturation.

References

  1. Study of optical absorption spectroscopy of Cu, Mn and Fe in tourmaline. Peer-reviewed mineralogical journal.Citation to be verified
  2. LMHC information sheet on Paraíba tourmaline nomenclature. Laboratory Manual Harmonisation Committee (LMHC).Citation to be verifiedInsert the current information sheet number, revision date and URL.

Author

Paraiba Ethiopia Editorial Team

The editorial team researches and writes Paraiba Ethiopia’s educational content on copper-bearing tourmaline, prioritising laboratory nomenclature and published gemological literature over trade claims.

Technical reviewer (assignment pending)

Independent gemological reviewer

Placeholder. A qualified gemologist will be named here once technical review of this page is complete. Until then, treat technical statements as editorially prepared but not yet independently reviewed.

First published 1 October 2026. Read our editorial policy