October Birthstone: Opal
October is blessed with two birthstones: opal and tourmaline. Opal is famous for its mesmerising play of colour, an optical phenomenon where the stone appears to contain shifting rainbows of light. Tourmaline offers an incredible range of colours, from watermelon pink-green to electric blue.
Quick Facts
Colour
Play of colour (all spectral colours)
Hardness
5.5–6.5 Mohs
Symbolism
Creativity, hope, and inspiration
Alternate Stones
Tourmaline
What is Opal?
Opal is a hydrated form of silica, containing 3 to 21 percent water within its structure. Its play of colour is caused by the diffraction of light through microscopic spheres of silica arranged in a grid-like pattern. Precious opal displays this play of colour, while common opal does not. Tourmaline is a boron silicate mineral that comes in more colours than any other gemstone. Notable varieties include rubellite (pink-red), indicolite (blue), paraiba (neon blue-green), and watermelon tourmaline (pink centre with green rind).
Properties
Colour
Opal displays a shifting play of colour across the spectrum, set against a body colour that can be white, black, crystal, or fire (orange). Tourmaline comes in every colour, with some crystals displaying multiple colours in a single stone.
Hardness
Opal is 5.5 to 6.5 Mohs, making it softer and requiring protective settings. Tourmaline is 7 to 7.5 Mohs, making it more suitable for everyday rings.
Origins
Australia produces over 90% of the world's precious opal, particularly from Lightning Ridge (black opal), Coober Pedy (white opal), and Queensland (boulder opal). Tourmaline is found in Brazil, Afghanistan, Mozambique, Nigeria, and the USA.
Lustre
Opal has a waxy to vitreous lustre with its unique internal play of colour. Tourmaline displays vitreous lustre with excellent clarity in faceted stones.
History
The ancient Romans considered opal the most precious gemstone because it contained the colours of all other stones. Pliny the Elder described opal as having "the fire of the carbuncle, the brilliant purple of the amethyst, and the sea green of the emerald." In the Middle Ages, opal was called "ophthalmios" (eye stone) and was believed to grant invisibility. Tourmaline's name comes from the Sinhalese word "tura mali," meaning "stone of mixed colours." It was first brought to Europe from Sri Lanka by Dutch traders in the 1700s.
Meaning & Symbolism
Opal symbolises creativity, hope, and inspiration. It is thought to amplify emotions and release inhibitions, encouraging freedom of expression. In crystal healing, opal is associated with spontaneity and imagination. Tourmaline is believed to promote compassion, tolerance, and prosperity. Black tourmaline in particular is considered one of the most powerful protective stones, thought to absorb negative energy.
How to Care for Opal
Opals require special care due to their water content and relatively low hardness. Never use ultrasonic or steam cleaners. Clean gently with a damp, soft cloth. Avoid extreme temperature changes, prolonged direct sunlight, and very dry environments, which can cause opal to crack or lose its play of colour. Store opal in a slightly damp cloth in a sealed container. Tourmaline can be cleaned with warm soapy water and is safe for ultrasonic cleaning in most cases.
Opal Jewellery Ideas
Australian black opal makes one of the most dramatic and unique centre stones for a ring, with no two stones ever alike. Opal pendants and earrings are safer choices than rings for everyday wear due to the stone's softness. Tourmaline's colour range offers endless possibilities, from a rubellite cocktail ring to a paraiba tourmaline pendant. Watermelon tourmaline slices, showing their natural pink and green zones, make distinctive and conversation-starting jewellery.
Shop Opal Jewellery
Looking for jewellery featuring opal or similar stones? Explore our handcrafted collections designed with ethically sourced stones.