Tourmaline: October's Colourful Birthstone
Tourmaline is October's second birthstone alongside opal, and the most colour-diverse gemstone in fine jewellery — occurring in every colour of the spectrum, including the famous bi-colour and tri-colour "watermelon" tourmalines that show multiple colours in a single crystal. This guide covers what tourmaline is, the main varieties, and how to choose one.
In short: Tourmaline is October's second birthstone alongside opal, and the most colour-diverse gemstone in fine jewellery — every colour of the spectrum, plus bi-colour and tri-colour "watermelon" varieties. Mohs 7-7.5, durable enough for daily-wear engagement rings. The premium variety, Paraiba tourmaline, displays neon blue-green colour and commands £5,000-15,000 per carat.
What is tourmaline
Tourmaline is a complex boron silicate that crystallises in long prismatic shapes. It scores 7–7.5 on the Mohs hardness scale — durable enough for everyday-wear jewellery but softer than sapphire or topaz. Tourmaline crystals are typically strongly pleochroic (showing different colours from different angles) and often show colour zoning along their length — which is what produces the bi-colour and watermelon varieties.
Tourmaline varieties
Rubellite (red and pink tourmaline) is the most-valuable variety, with vivid raspberry-red specimens commanding fine-ruby prices. Paraiba tourmaline (electric blue-green from Brazil, Nigeria, and Mozambique) is rarer and more expensive — copper-bearing stones with neon colour. Chrome tourmaline (intense green from Tanzania) competes with emerald for daily-wear suitability. Watermelon tourmaline shows pink core with green rim and is prized as a unique collector and statement piece. Indicolite (blue tourmaline) and dravite (yellow-brown) round out the major varieties.
Origin and supply
Brazil is the historical major source for fine tourmaline including the original Paraiba discovery. Nigeria and Mozambique also produce Paraiba-type tourmalines. Afghanistan and Pakistan produce excellent pink and bi-colour stones. Madagascar, Mozambique, and Tanzania supply the broader colour range. Supply remains active across multiple countries, which keeps pricing more accessible than for single-source gemstones like tanzanite.
Pricing
A 1-carat fine pink rubellite tourmaline starts around £400–£900. A vivid green chrome tourmaline in similar size runs £300–£700. Paraiba tourmaline is the high-end of the category — a 1-carat fine Paraiba commands £5,000–£15,000 depending on saturation and origin (Brazilian Paraiba being most valuable). Watermelon tourmaline pricing varies widely with colour zoning quality — a clean bi-colour stone runs £500–£2,000 per carat. For value and visual impact, tourmaline delivers more than almost any other coloured gemstone.
Tourmaline in jewellery
Tourmaline's 7-7.5 hardness suits engagement rings and daily-wear pieces with reasonable care. The crystal's tendency to form long shapes means tourmaline is often cut as emerald-cut or elongated cushion to preserve maximum carat weight — a stylistic match for tall, oval, or elongated settings. Bi-colour and watermelon stones are typically cut as flat slices or rectangular tablets to display the colour transition; these work best in pendants and earrings where the flat face is visible.
Frequently Asked Questions
Is tourmaline a hard enough stone for an engagement ring?
Yes — at 7-7.5 Mohs, tourmaline is durable enough for engagement rings with reasonable care. It is softer than sapphire (9) but harder than opal (5.5-6.5). For active lifestyles or rough-handling environments, a bezel setting protects the stone effectively. Routine cleaning and annual prong inspection keep tourmaline rings looking their best for decades.
What is Paraiba tourmaline and why is it so expensive?
Paraiba tourmaline is a copper-bearing variety that displays neon blue-green colour found in almost no other gemstone. Discovered in the Paraiba state of Brazil in 1989, the original deposit was small and quickly mined out. Nigerian and Mozambican Paraiba-type tourmalines (also copper-bearing) followed but generally show less intense colour. Top Brazilian Paraiba commands £15,000-50,000 per carat for vivid stones — among the highest per-carat prices in the gem world.
What is watermelon tourmaline?
Watermelon tourmaline is a bi-colour variety showing pink in the centre of the crystal and green at the edges — resembling a slice of watermelon when cut perpendicular to the crystal length. The colour zoning is natural and varies stone to stone. Tri-colour watermelon (pink-white-green) is rarer and more valuable. Watermelon tourmaline is typically cut as flat slices or rectangular tablets and works best in pendants where the face is visible.
How does tourmaline compare to other coloured gemstones?
Tourmaline's colour range exceeds any single corundum (sapphire) or beryl (emerald, aquamarine) variety. It is generally softer than sapphire (9) but harder than emerald (7.5-8). Pricing is lower per carat than ruby or sapphire of equivalent colour — except for Paraiba and very fine rubellite. For buyers wanting an unusual colour or bi-colour effect at an accessible price, tourmaline is often the best choice.
How do I care for tourmaline jewellery?
Tourmaline is generally robust enough for warm-water and mild-soap cleaning. Avoid ultrasonic and steam cleaning for tourmaline with visible inclusions, as thermal shock can crack the stone along inclusion planes. Store separately from harder stones to avoid scratching. For ring-set tourmaline, annual prong inspection by a jeweller is recommended; the stone is durable but the setting wears faster than the stone itself.
Explore tourmaline jewellery at Reve
Reve Diamonds creates bespoke tourmaline pendants, earrings, and rings at our London showroom. Browse our pendants & necklaces collection for inspiration or contact us for a custom commission with a hand-selected tourmaline centre stone.
