Chemistry · Gemology & Science
Chemical Composition of Paraíba Tourmaline
Tourmaline is a complex borosilicate whose structure accommodates many elements. In copper-bearing tourmaline, small quantities of copper and manganese have an outsized effect on colour.
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- Paraiba Ethiopia Editorial Team
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- Review pending
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What is tourmaline made of?
Tourmaline is a borosilicate with a general formula written XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W. In elbaite, lithium and aluminium occupy the Y site, where copper can also substitute.
Which elements are measured?
Chromophores (Cu, Mn, Fe, Ti) and trace elements used for origin work (such as Ga and Pb) are typically measured.
Chromophore and trace-element panel — template
Template — no values yetPrincipal chromophore discussed for blue to green colour in Paraíba-type tourmaline
Pending · ppmw · LA-ICP-MS / EDXRF
Mn³⁺ can add pink–violet components; Mn²⁺ is largely colourless
Pending · ppmw · LA-ICP-MS / EDXRF
Can shift colour toward darker blue or green and reduce brightness
Pending · ppmw · LA-ICP-MS / EDXRF
Participates in charge-transfer interactions with Fe in some tourmalines
Pending · ppmw · LA-ICP-MS
Trace element sometimes used in origin discrimination
Pending · ppmw · LA-ICP-MS
Trace element sometimes used in origin discrimination
Pending · ppmw · LA-ICP-MS
References
- Reference text on tourmaline-supergroup mineralogy (elbaite and related species). Academic publisher.Citation to be verified
- Study of trace-element approaches to origin determination of Cu-bearing tourmaline. Peer-reviewed analytical or gemological journal.Citation to be verified
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
Continue reading
- ChemistryThe Role of Copper in Paraíba TourmalineHow copper colours tourmaline, how it is detected and why its presence defines the Paraíba variety.
- ChemistryThe Role of Iron in Paraíba TourmalineHow iron affects the colour of copper-bearing tourmaline and why iron-coloured tourmaline can be mistaken for Paraíba.
- OriginOrigin Determination of Paraíba TourmalineHow laboratories determine the geographic origin of copper-bearing tourmaline, and why some stones receive no origin opinion.