October birthstone
Opal, Tourmaline
Opal has been linked to hope and inspiration since ancient times, its shifting colors seen as a kind of visible imagination, no two stones ever catching light the same way twice. That unpredictability became part of its meaning: opal is often associated with embracing change and trusting that beauty can come from complexity rather than uniformity.
Tourmaline's wide color range, sometimes several colors in a single crystal, has made it a symbol of balance and self understanding. Different colors carry their own associations, from calm to courage, but the stone as a whole is tied to emotional steadiness and the idea that strength often comes from accepting many sides of yourself at once.
Opal ranges from milky white and pale blue to black opal with deep, smoldering tones, all crossed by flashes of red, green, and blue light. That shifting color has long been associated with imagination and hope, since the stone seems to hold movement and change inside something otherwise still and solid.
October's birthstones suit people born under Libra (September 23 to October 22) or Scorpio (October 23 to November 21). Libra's love of harmony pairs naturally with opal's shifting balance of color, while Scorpio's intensity finds a match in tourmaline's depth and range. Both stones also suit anyone drawn to gems that feel personal and a little unpredictable.
Ancient Romans considered opal a symbol of hope and purity, and Pliny the Elder praised it as combining the finest qualities of other gems. Indigenous Australian communities have long connected to opal through the land itself, since Australia produces most of the world's supply today. Tourmaline entered Western gem trade later, popularized in the 1800s after Dutch traders brought colorful crystals from Sri Lanka back to Europe, where they were initially mistaken for other gems.
Opal is soft for a gemstone, ranking 5.5 to 6.5 on the Mohs scale, and contains a small amount of water, so it can crack if it dries out or takes a hard knock. Clean it gently with a soft cloth and lukewarm water, avoid ultrasonic cleaners and harsh chemicals, and store it away from other jewelry to prevent scratches. Opal rings are best saved for lighter, everyday wear rather than heavy work.
Birthstones by month
Curious what else your month says about you? Read your zodiac sign or explore color meanings.
Frequently asked questions
›What is the October birthstone?
October has two official birthstones: opal and tourmaline. Opal, known for its rainbow flashes of color, is the more traditional choice, while tourmaline, which comes in almost every color, offers a colorful alternative. Both are widely recognized by jewelers and gemological organizations, so either one is considered correct for someone born in October.
›What color is the October birthstone?
Opal isn't one color; it ranges from milky white to blue gray to black, all crossed by flashes of red, green, and blue light called play of color. Tourmaline is even more varied, appearing in pink, green, blue, black, and bicolor combinations, which is why October's birthstone identity is really about variety rather than a single shade.
›Why does opal 'flash' different colors?
Opal's play of color comes from tiny silica spheres arranged in a grid like pattern inside the stone. As light passes through and bends around these spheres, it splits into flashes of spectral color. The size and arrangement of the spheres determine which colors appear, which is why every opal's pattern is unique.
›Is opal a durable stone for everyday jewelry?
Opal is softer than many popular gemstones, ranking 5.5 to 6.5 on the Mohs hardness scale, so it can scratch or crack more easily than sapphire or diamond. It works well in earrings, pendants, and occasional wear rings, but it should be protected from hard knocks, extreme dryness, and harsh cleaning chemicals.