Sapphire and Ruby Engagement Rings: A Guide to Coloured Stone Centrepieces

While diamonds remain the most common choice for engagement ring centre stones, coloured gemstones — particularly sapphires and rubies — have a long and storied history in engagement jewellery, and continue to appeal to couples who want a centre stone with more colour, character, and individuality.

Why Sapphires and Rubies

Both sapphire and ruby are varieties of the mineral corundum, which makes them exceptionally hard and durable — a 9 on the Mohs hardness scale, just below diamond's 10. This durability is a major reason both stones have been used in fine jewellery for centuries and remain practical choices for a ring worn daily.

Sapphires occur in nearly every colour except red (a red corundum is, by definition, a ruby), but the deep, rich blue sapphire remains the most iconic choice for engagement rings — made famous in part by historically significant royal engagement rings. Rubies range from a brighter red to a deeper, more purplish red, with the most prized rubies showing a vivid, saturated colour often described as "pigeon's blood."

What to Look for in Colour

Unlike diamonds, where the goal is typically the absence of colour, with sapphires and rubies, colour is the primary value driver. For sapphires, a medium-to-darker, vivid blue with good saturation is generally most prized — stones that are too dark can lose brilliance, while stones that are too light may look washed out. For rubies, a vivid red with good saturation and minimal brown or purple undertone is typically most desirable.

It's worth seeing coloured stones in person, or at least under a few different lighting conditions via video, before purchasing — sapphires and rubies can shift in appearance noticeably between daylight, indoor lighting, and direct sun in ways that are harder to predict from a single photo than with a diamond.

Heat Treatment: A Normal Part of the Market

The vast majority of sapphires and rubies on the market today are heat-treated — a process that improves colour and clarity and has been standard industry practice for decades. Heat-treated stones are not considered "fake" or lesser; they are genuine sapphires and rubies that have undergone a widely accepted enhancement process, and they're priced accordingly lower than untreated stones of comparable visual quality. Untreated stones with excellent colour are considerably rarer and command a significant premium. For most couples, a quality heat-treated stone offers excellent value and beauty.

Durability in Daily Wear

The hardness of sapphire and ruby means both hold up very well to the daily knocks of regular wear — considerably better than softer coloured gemstones like emerald or opal, which require more careful handling. This makes sapphire and ruby genuinely practical choices for an engagement ring meant to be worn every day, not just special-occasion pieces.

Setting Considerations for Coloured Centre Stones

A claw setting works well for sapphires and rubies, allowing light to enter and showcase the stone's colour from multiple angles. Because these stones don't rely on colourlessness, a halo of diamonds around a sapphire or ruby centre stone creates striking contrast — white diamonds framing a saturated blue or red centre stone is one of the most popular combinations for coloured stone engagement rings.

White gold and platinum settings tend to make the colour of the centre stone "pop" through contrast, while yellow gold settings create a warmer, more vintage-feeling overall look — particularly with rubies, where the warm tones of yellow gold can complement the stone's red hue.

A Choice With Its Own Character

Choosing a sapphire or ruby centre stone isn't a compromise or alternative to diamond — it's a deliberate choice for a ring with its own distinct character, colour, and presence. For couples drawn to colour, durability, and a centre stone that feels less common, sapphire and ruby remain two of the most rewarding choices available.

If a coloured centre stone has caught your eye, we'd be glad to source options and talk through treatment, setting, and design choices that bring out the best in the stone. Book a consultation to explore further.