What is the birthstone for October?
October has two birthstones; tourmaline and opal. Look at what makes these stunning gems unique.
Is October’s birthstone opal or tourmaline?
What is a tourmaline?
Now for the science part: tourmaline is the term we use for a wide range of boron silicate minerals. The stones are variously compounded with elements such as potassium, aluminium, iron, sodium and magnesium. And what does this mean? That the gemstone comes in the widest variety of colours of any gemstone in the world. Not only are these translucent stones found in colours ranging from pink through purple and onto green but sometimes this can happen in the same stone, resulting in the famous Watermelon Tourmaline which resembles an eye-watering slice of the distinctive fruit.
What is an opal?
Opals are an amorphous form of silica: a mineraloid. It is formed in the fissures and cracks in rocks where water has evaporated, leaving the silica behind. Opals, like their October companions, tourmaline, are multicoloured, but often within the same stone. They are pearlescent, exhibiting a shimmering array of colours, even more vivid in some varieties such as Fire opal or Blue opal. Opals are crafted into cabochon shaped stones, though many jewellers also work with doublets and triplets: layers of opal backed by a darker stone and topped by quartz.
Both tourmalines and opals have been used in fine jewellery for centuries. Opals were prized by the Romans, Ancient Greek and Arab cultures and they can be seen set into fine Edwardian and Victorian jewellery. Tourmaline’s history is harder to chart since it was often mistaken for the red rubies, green emeralds and blue sapphires it can resemble. Revered by the Chinese empress Tz’u Hsi and used in the Russian Crown Jewels, they grew in popularity in the 20th Century.
Whether it is the deep translucent beauty of a tourmaline or the seductive shimmer of the opal, your choice of stone as an October baby will be as eye-catching as it is unique. No bad thing for a birthstone.
Shop our October birthstone jewellery collection here.