Tourmaline: October's Colorful Birthstone
Tourmaline is October's second birthstone alongside opal, and the most color-diverse gemstone in fine jewelry — occurring in every color of the spectrum, including the famous bi-color and tri-color "watermelon" tourmalines that show multiple colors 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 jewelry — 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 $5,000-50,000 per carat; standard pink rubellite or chrome green starts around $400-900 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 jewelry but softer than sapphire or topaz. Tourmaline crystals are typically strongly pleochroic (showing different colors from different angles) and often show color zoning along their length — which is what produces the bi-color 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 color. 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-color stones. Madagascar, Mozambique, and Tanzania supply the broader color range. Supply remains active across multiple countries, which keeps pricing more accessible than for single-source gemstones like tanzanite.