GIA certified paraiba tourmaline oval cut. Weighs 3.66 carats. Measures 10.68 x 9.31 x 5.28 mm. Sold with original GIA paperwork. One of the most striking facts about Paraíba Tourmaline is that its vivid neon-blue to green colour comes from unusually high concentrations of copper, plus some manganese—making it unique among tourmalines (other tourmalines typically derive their colours from iron, chromium, vanadium, etc.)