If you were born in October, your birthstone is opal: the one stone that refuses to settle on a single colour. Tilt it in the light and it flashes blue, green, pink and orange at once, a shifting fire no two stones share. It is the most individual gem on the calendar, which feels fitting for the people who wear it.

October is also a two-stone month. Alongside opal it has tourmaline, a gem that comes in more colours than any other, so October births have an unusually rich choice. We cover both below. For every month and stone, see our birthstones by month chart.

What colour is opal, and what is play of colour?

Opal's magic is called play of colour: those darting flashes of spectral colour that move as the stone, or your eye, shifts. They are caused by tiny spheres of silica inside the stone bending light like a prism. No two opals show the same pattern, which is a large part of why they are so loved.

The body colour underneath varies too. White opal has a pale background, black opal a dark one that makes the colours leap out and is the most prized of all, and fire opal a warm orange-to-red body. So the honest answer to what colour is October's birthstone is: all of them at once.

What opal means

Opal has long been a stone of hope, creativity and inspiration. Because it seems to contain every colour, it was thought to hold the virtues of all other gems at once, and the Romans considered it a symbol of hope and purity. It is a fitting stone for anyone who values individuality and imagination.

The name is thought to come from the Sanskrit upala, simply meaning precious stone, by way of the Greek opallios.

Is opal really unlucky?

No, and the superstition is surprisingly recent. For most of history opal was considered one of the luckiest stones there was. Its bad reputation is often traced to a single Victorian novel, Sir Walter Scott's Anne of Geierstein of 1829, in which an opal loses its colour and its owner dies. The story caught the public imagination and, the tale goes, opal sales fell sharply for years. It is fiction, nothing more. If your birthday falls in October, opal is simply your stone, and a beautiful one.

Opal jewellery, and how to wear it

Opal's shifting colour means it goes with far more than you would expect, and it looks wonderful in warm yellow gold. An opal necklace or pendant is the easiest and safest way to wear it, and a bezel setting wraps the stone in a protective rim of gold.

Because opal is soft and contains water, it is happiest in a pendant or earrings rather than a ring, which takes the most knocks. Every Argent & Asher piece is handcrafted to order in solid, hallmarked gold, so an October birthstone necklace is made to be kept.

Tourmaline, October's other stone

If opal feels too delicate, tourmaline is a wonderful alternative, and it has a party trick of its own: it comes in more colours than any other gemstone. There is raspberry pink tourmaline, cool green tourmaline, and the extraordinary watermelon tourmaline, pink at the centre and green at the rim in a single crystal.

Rarest of all is neon blue-green Paraiba tourmaline, one of the most valuable coloured stones in the world. Tourmaline is also harder than opal, at 7 to 7.5, which makes it a better choice for a ring worn every day.

Caring for opal

Opal is soft, around 5.5 to 6.5 on the hardness scale, and it holds water, so it needs gentle care. Keep it away from heat, harsh chemicals, perfume and ultrasonic cleaners, all of which can dry it out or damage the surface. Clean it only with a soft, damp cloth, and store it away from very dry heat. Worn as a pendant and looked after, an opal will keep its fire for a lifetime.

October birthstone questions

What is the October birthstone?

October has two birthstones: opal, famous for its shifting play of colour, and tourmaline, which occurs in more colours than any other gem. Opal is the traditional choice; tourmaline is the harder-wearing alternative.

What colour is opal?

Opal shows a shifting play of every spectral colour, blue, green, pink and orange, over a body that may be white, black or fiery orange. Its colour changes as the stone moves, which is exactly why no two opals are alike.

What does opal mean?

Opal is a stone of hope, creativity and inspiration. Because it seems to hold every colour, it was thought to carry the virtues of all other gems, and the Romans saw it as a symbol of hope and purity.

Is opal unlucky?

No. For most of history opal was considered lucky. The superstition dates only to a Victorian novel, Sir Walter Scott's Anne of Geierstein (1829), and has no basis. If October is your birth month, opal is simply your stone.

What is October's other birthstone?

Tourmaline. It comes in an unrivalled range of colours, from pink and green to the two-tone watermelon and the rare neon Paraiba, and at 7 to 7.5 on the hardness scale it is more durable than opal, making it a good choice for rings.

Is opal good for everyday jewellery?

Opal is soft and holds water, so it is best worn as a necklace, pendant or earrings rather than a ring, and kept away from heat and chemicals. Set in solid gold with a protective bezel, it wears beautifully. For an everyday ring, tourmaline is the tougher October choice.