Sapphire, Emerald or Ruby? The Complete Guide to Coloured Gemstone Engagement Rings

For most of the last century, engagement ring meant a white diamond. That's changing fast. Coloured stones are one of 2026's biggest engagement ring trends, and plenty of couples have realised that a deep blue sapphire or a vivid green emerald says something a diamond can't.

It isn't new, of course. Sapphires, rubies and emeralds have been set in engagement rings for centuries. In Britain the most famous example is the oval sapphire ring given to Lady Diana Spencer in 1981, now worn by the Princess of Wales.

Which gemstones can handle everyday wear?

An engagement ring is worn every day and knocked against desks, door handles and car keys. So before falling for a colour, it's worth knowing how tough each stone is. Hardness is measured on the Mohs scale, from 1 to 10. It tells you how well a stone resists scratching.

Hardness isn't the whole story, though. Emeralds are reasonably hard, but they almost always contain natural inclusions that make them more prone to chipping from a sharp knock. That's why the setting matters as much as the stone.

Sapphire: the best all-rounder

If you want colour without worry, choose sapphire. At 9 on the Mohs scale, it's second only to diamond, so it copes happily with daily life. It's also far more varied than most people realise: sapphire covers every colour of the mineral corundum except red, which is ruby.

Blue sapphire is the classic. Look for a rich, even blue that isn't so dark it looks black indoors. Teal sapphires are having a real moment: they sit between blue and green and can shift between the two in different light, often at better value than a top blue of the same size. Pink and yellow sapphires are soft and romantic, or sunny and bright, with the same toughness.

Blue sapphire0.95ct oval, halo£1,400View ringBlue sapphire1.10ct cushion, double halo£2,400View ringBlue sapphire1.20ct round, halo£3,700View ringTeal sapphire1.11ct pear£2,000View ringTeal sapphire2.52ct oval£3,200View ringPink sapphire0.66ct round, halo£1,000View ring

See all our blue sapphire and yellow sapphire engagement rings.

Ruby: passion with real strength

Ruby is sapphire's red sibling, the same mineral in a different colour, so it's just as tough at 9 on the Mohs scale. It has stood for love and passion for centuries, which makes it a natural fit for an engagement ring.

The colour to look for is a strong, pure red. Stones that lean slightly pink or purple can still be beautiful, but the most valuable rubies are a saturated red.

Thai ruby0.90ct trilogy with diamonds£1,650View ringBurmese ruby1.08ct oval£2,400View ringBurmese ruby1.01ct with F VS1 diamonds£3,600View ring

See all our ruby engagement rings.

Emerald: the most romantic choice

Nothing quite matches the green of a fine emerald. It has a vintage, almost Art Deco glamour, and it looks wonderful in yellow gold.

The honest trade-off is care. Emeralds almost always contain natural inclusions, which the trade affectionately calls the stone's jardin, or garden. They're part of an emerald's character, but they also make it more vulnerable to a hard knock. Most emeralds are also treated with oil or resin to improve clarity, which is normal and accepted, and another reason to treat them gently.

Colombian or Zambian? Colombian emeralds are the most famous, admired for a warm, vivid green. Zambian emeralds tend towards a slightly cooler, bluish green and are often very clean. Both can be outstanding.

Colombian emerald0.40ct square emerald cut£1,250View ringZambian emerald0.60ct oval£1,700View ringColombian emerald1.68ct halo, yellow gold£2,200View ringColombian emerald0.93ct halo, platinum£4,150View ring

See all our emerald engagement rings.

Beyond the big three

A few other stones make beautiful and distinctive engagement rings. Aquamarine is a calm, watery blue and good value for its size, though a little softer than sapphire. Alexandrite is the magic trick of the gem world, typically greenish in daylight and reddish-purple under warm indoor light. Topaz gives bright, affordable colour. And a natural fancy-coloured diamond combines diamond's hardness with real colour.

Blue topaz1.70ct oval, platinum£1,350View ringAquamarine0.84ct with diamonds£2,000View ringFancy coloured diamond0.70ct GIA, double halo£8,500View ringAlexandrite7.01ct round, platinum£20,800View ring

How to judge a coloured gemstone's quality

Diamonds have the 4Cs. Coloured stones are judged a little differently, and colour matters most.

1. Colour. Look for a rich, even colour that's neither too pale nor so dark it looks black away from bright light. View it in daylight and indoor light, as some shift noticeably.
2. Clarity. Sapphires and rubies should look clean to the naked eye. Emeralds are expected to have some inclusions, so judge them on overall beauty, not perfection.
3. Cut. A well-cut stone looks lively across its whole face. Watch for a window, a pale, washed-out patch in the middle where light leaks straight through.
4. Origin. Some origins, such as Burmese ruby or Colombian emerald, carry a premium. A beautiful stone from a less famous source can be excellent value.
5. Treatment. Heating sapphires and rubies to improve colour is standard and permanent, and oiling emeralds is standard too. Untreated stones are rarer and cost more. A good jeweller will always tell you how a stone has been treated.
6. Certification. For a significant stone, an independent gemmological report confirms what it is, where it may come from and how it's been treated. Ask us which of our stones come with one.

Choosing the setting and metal

Frequently asked questions

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