Paraiba Tourmaline Identification Guide
How to identify copper-bearing Paraiba tourmaline by its electric neon blue-green glow and separate it from imitations.
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What Paraiba Tourmaline Looks Like
Paraiba tourmaline is a copper- (and often manganese-) bearing variety of elbaite tourmaline famous for an intense, almost glowing "neon" or "electric" blue to blue-green (and sometimes violet) color. The defining feature is the vivid, saturated, internally lit appearance caused by copper. It is transparent, with a vitreous luster, and typically faceted because of its high value. Trade usage applies the name to copper-bearing tourmalines from Brazil (Paraiba), Nigeria, and Mozambique.
- Color: neon blue, "Windex" blue, turquoise, blue-green, rarely violet
- Transparency: transparent
- Luster: vitreous
- Habit: prismatic crystals with rounded-triangular cross-section, vertical striations
Step-by-Step Field ID Checklist
- Judge the color. The glowing, electric saturation is the hallmark; ordinary blue tourmaline looks duller.
- Look for striations. Tourmaline crystals show lengthwise grooves and a rounded triangular cross-section.
- Check pleochroism. Tourmaline shows different color/intensity when viewed along different axes.
- Hardness test. Mohs 7-7.5; scratches glass.
- Inspect inclusions. Natural copper-bearing tourmaline often has fine needle/feather inclusions; suspiciously clean = check for synthetics.
- Confirm copper by lab. Only spectroscopy/chemistry proves the copper that defines true Paraiba.
Key Diagnostic Tests
- Mohs hardness: 7-7.5.
- Streak: white.
- Fracture: uneven to conchoidal; poor cleavage.
- Density: ~3.0-3.1 g/cm3.
- Optics: strongly pleochroic, doubly refractive; copper signature confirmed by EDXRF/spectroscopy.
Common Look-Alikes and How to Tell Them Apart
- Ordinary blue (indicolite) tourmaline: lacks the neon glow; without copper it is not "Paraiba."
- Apatite: softer (5), more easily scratched, and brittle; can mimic the neon blue but fails the hardness test.
- Blue topaz / treated zircon: different optical properties and density; topaz has distinct cleavage.
- Glass / synthetic spinel imitations: singly refractive, no pleochroism, often with gas bubbles.
- Treated/coated stones: color may be surface-bound; check girdle and facet junctions under magnification.
Where It Is Found
The original and most prized material comes from Paraiba and Rio Grande do Norte states in Brazil. Copper-bearing tourmaline marketed as "Paraiba-type" is also mined in Nigeria and Mozambique. All form in granitic pegmatites enriched in copper.
Frequently asked questions
How can you tell if it is real Paraiba tourmaline?
True Paraiba is copper-bearing elbaite with an electric neon blue to blue-green glow, hardness 7-7.5, strong pleochroism, and double refraction; the defining copper content must be confirmed by spectroscopy.
What does Paraiba tourmaline look like?
It shows an intensely saturated, almost glowing neon blue, turquoise, or blue-green color that appears internally lit, set in a transversely striated transparent crystal.
Paraiba tourmaline vs apatite - how do you tell them apart?
Both can be neon blue, but apatite is much softer (Mohs 5) and is easily scratched, while Paraiba tourmaline is hard (7-7.5) and scratches glass.
Where does Paraiba tourmaline come from?
Originally from Paraiba and Rio Grande do Norte in Brazil, with copper-bearing Paraiba-type material also from Nigeria and Mozambique.