The October birthstone is the Pink Opal gemstone. This is also the gemstone associated with the Zodiac sign Libra. The Romans believed that Opal was the most important and symbolic stone of all the gemstones because of its wide array of colours. Pink Opal gemstones vary from palest pink to a bright pink and are among the most popular opals. Pink Opal birthstones are believed to encourage love kindness and friendship. They make stunning and feminine necklaces, earrings, studs and bangles. Discover our range of October birthstone jewellery.