Opal

Opal is famous for its mesmerizing play of colour, displaying brilliant flashes of the rainbow that shift with movement and light. Each opal is truly unique, with patterns and colours ranging from fiery reds and oranges to serene blues and greens. Opals are hydrated silica and relatively soft, with a hardness of 5.5–6.5 on the Mohs scale, so they require some care, especially when used in rings. October’s birthstone, opal has inspired countless myths and was prized in Roman and medieval European jewellery. Opals are a symbol of inspiration and creativity, making them a perfect gemstone for a truly distinctive and artistic engagement ring. 

Hardness: 5.5–6.5 (Mohs scale), best suited to protected settings or occasional-wear rings, as opal can scratch or chip more easily than other gems. 

Colour: Ranges from milky white to deep black, with vivid flashes of red, green, blue, yellow and purple. The most valued opals show a full spectrum of colours. 

Origin: Australia is the world’s premier opal source, especially for black opals, with notable deposits also in Ethiopia and Mexico (fire opal). 

Notable Fact: Opals contain up to 20% water and are sensitive to sudden temperature changes. Ancient Romans believed opal symbolised hope and purity.