Paraíba Tourmaline
Tormalina Paraíba
Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ Properties
- Color
- Neon blue, turquoise-green
- Luster
- Vitreous
- Density
- 3.06 g/cm³
- Category
- Gem
Paraíba tourmaline is a variety of cupriferous elbaite discovered in 1989 in the Brazilian state of Paraíba. It is renowned for its unique neon blue-turquoise color in mineralogy — produced by the presence of copper within the crystal lattice.
The extraordinary color derives from the presence of copper (Cu²⁺) in the crystal lattice. Typical tourmalines owe their colors to iron, manganese, or chromium. Copper creates an internal luminescence effect that gemologists describe as "neon": the stone appears to emit its own light even under reduced illumination conditions.
The discovery is credited to Heitor Dimas Barbosa, who excavated for years in the hills of São José da Batalha. In 1989, his perseverance was rewarded with findings that revolutionized the global gemological market.
Belongs to the tourmaline supergroup, elbaite series. The refractive index ranges between 1.619 and 1.641, with birefringence of 0.018–0.022. Characteristic inclusions include growth channels parallel to the c-axis and two-phase fluid inclusions. Determination of geographic origin requires LA-ICP-MS analysis to quantify Cu, Zn, Ga, Sr, Sn, and Pb.
Mining localities
- São José da Batalha, Paraíba, Brasile
- Rio Grande do Norte, Brasile
- Merelani Hills, Mozambico
- Nigeria
