October has two birthstones: the opal, famous for its mesmerising play-of-colour, and tourmaline, which occurs in more colours than any other gemstone.
Gemstone
Opal & Tourmaline
Colour
Opal: rainbow play-of-colour | Tourmaline: every colour
Hardness
Opal: 5.5–6.5 Mohs | Tourmaline: 7–7.5 Mohs
Symbolism
Creativity, hope, and emotional healing
Opals display a phenomenon called "play-of-colour" — flashes of spectral colour that dance across the stone as it moves. This effect is caused by microscopic spheres of silica that diffract light into its component colours. No two opals are alike, making each stone truly unique.
Tourmaline is the most colour-diverse gemstone, occurring in every colour of the spectrum. The most prized variety is Paraíba tourmaline — a neon blue-green stone from Brazil that can rival sapphires in price. Pink and green ("watermelon") tourmalines are also highly sought after.
Australian black opals are the most valuable variety, displaying vivid play-of-colour against a dark body tone. Ethiopian opals have emerged as a popular and more affordable alternative, offering similar beauty at accessible prices.
Opals require protective settings due to their softness (5.5-6.5 Mohs) — bezel settings are ideal. Tourmaline is more durable (7-7.5 Mohs) and suitable for rings. Both stones create unique, conversation-starting jewellery.
October has two birthstones: opal and tourmaline. Opal is known for its unique play-of-colour, while tourmaline occurs in more colours than any other gemstone, from pink and green to rare neon blue Paraíba.
No — the superstition about opals bringing bad luck dates from a 19th-century novel. For centuries before that, opals were considered among the luckiest stones. In the Middle Ages, opals were believed to possess the virtues of every gemstone whose colour appeared in their play-of-colour.
Opals are softer than most gemstones (5.5-6.5 Mohs) and require more care than diamonds or sapphires. They are best suited for pendants, earrings, and occasion rings rather than everyday rings. Avoid exposing opals to sudden temperature changes.