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Paraiba Tourmaline
Specimen | Catalog Number | Locality | Weight |
---|---|---|---|
Elbaite | NMNH 176585 | Brazil, Paraiba |
Tourmaline is normally colored by trace impurities of iron, manganese, chromium and vanadium. However, Paraiba tourmaline, discovered in Brazil in the late 1980s, owes its intense blue color to the presence of copper. The combination of the copper along with some manganese in Paraiba tourmaline gives rise to a variety of beautiful colors ranging from emerald green to mint green, neon blue to sapphire blue, to indigo and purple. Copper in high concentrations is responsible for the rare and highly-prized blue and green hues, while violet and purple colors are due to the greater presence of manganese. Faceted Paraiba gems rarely come in sizes over a few carats as the rough is typically fractured when discovered. Due to the uniquely intense colors and scarcity, these tourmalines command extremely high prices, which continue to rise, reaching all time highs for tourmaline gems. In 1989 when the first crystals were mined, there was a period of frantic activity, but 5 years later the deposits apparently were exhausted. In 2001, vivid blue-green tourmalines from Nigeria, resembling the Brazilian Paraibas in color and chemistry (also copper-bearing), appeared in the market. A later find in Mozambique of blue to green tourmalines were also found to be copper-bearing (cuprian) gems. The trade now commonly refers to the neon greenish-blue variety of cuprian-tourmalines as Paraiba, regardless of locality. The natural tourmaline crystal pictured here from Paraiba, Brazil, weighs 310ct and is an intense greenish-blue color. It is the first such crystal in the National Gem Collection.