Paraiba Tourmaline has a specific gravity of 3.06 and a refractive index of 1.624–1.644, with a Mohs hardness of 7.0–7.5. It is uniaxial −.

Physical & Optical Properties

RI Range1.624–1.644
SG Range3.02–3.10
SG Typical3.06
Hardness (Mohs)7–7.5
Crystal SystemTrigonal
Optic CharacterDR Uniaxial (−)
Birefringence0.018
Dispersion0.017
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterGreen
PleochroismStrong Dichroic
ColorsBlue Violet, Green
SpeciesTourmaline
VarietyParaiba
Blue VioletGreen

Key Differentiators

Common Simulants

Commonly Confused With

Commonly confused with: Aquamarine, Glass.

Treatments

Price Context

Natural — low ($/ct)$3,000
Natural — high ($/ct)$50,000
NotePer carat; fine Brazilian neon blue under 1 ct can exceed $50,000/ct; Mozambique and Nigerian Cu-bearing material is significantly less (1/5 to 1/10 of Brazilian); heat treatment universally accepted, no discount

Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.

Related Comparisons

Measurement Guides

Identifying a paraiba tourmaline? GemID walks through these tests in order — RI, SG, fluorescence, and more.

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Studying for the GIA, FGA, or FEEG practical? Paraiba Tourmaline is one of the 130 species in GemID’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.

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