A coloured gemstone changes more than the appearance of an engagement ring. It can become the starting point for the metal, setting, surrounding stones and the way the ring responds to light.
British designer Andrew Geoghegan works particularly with sapphire, ruby, emerald, tsavorite and coloured diamonds, helping clients choose by colour, durability and design rather than convention.
Why colour, why now?
More personal than convention
Couples increasingly want a ring that says something about them. Sapphire, ruby, emerald and other natural gemstones allow colour to become part of the ring's identity from the beginning.
The changing diamond market is part of the context. Natural and lab-grown diamonds may look the same, but their provenance, rarity and story are different. Andrew believes some of the public have also lost confidence in diamonds as prices have shifted and the instantly available “Insta-diamond” has changed how rarity and long-term value are perceived. For those buyers, coloured gemstones offer something that feels more individual, expressive and emotionally distinct.
Choosing a non-diamond engagement ring is not simply a reaction against convention. It is a positive design decision. Blue can read as calm, red as passionate and green as grounded. What the colour means is ultimately personal to the wearer.
Made for real life
How durable are coloured stone engagement rings?
Durability depends on the stone. Ruby and sapphire sit at 9 on the Mohs hardness scale, making them two of the most practical choices for daily wear. Softer stones can still work, but may need a protective setting or a more careful wearer.
Stone
Mohs hardness
Everyday wear notes
Coloured diamond
10
The hardest gemstone of any colour. Wears exactly like a white diamond.
Sapphire
9
Exceptionally practical and available in blue, pink, yellow, green, orange and rare padparadscha tones.
Ruby
9
As durable as sapphire. A confident choice for frequent wear.
Alexandrite
8.5
Very durable, with a colour shift between daylight and indoor light.
Tsavorite garnet
7–7.5
No cleavage plane, making it a strong green alternative to emerald. Like any gemstone, it can still chip if struck, so the setting and the wearer's habits matter.
Emerald
7.5–8
Naturally included and more brittle than its number suggests. Best with protection or a careful wearer.
Morganite
7.5–8
A pink beryl. Suitable for daily wear with reasonable care.
Aquamarine
7.5–8
Paler and less intense than sapphire. Treat with the same care as morganite.
Topaz
8
Hard, but with perfect cleavage. A sharp knock in the wrong direction can split it.
Zircon
7.5
A genuine natural gemstone, distinct from cubic zirconia, and reasonably hard.
Tourmaline
7–7.5
A wide colour range, including blue indicolite. Suitable with a degree of care.
Amethyst
7
A quartz gemstone. A good-quality example holds up well with mindful wear.
Tanzanite
6–7
Noticeably softer. Best suited to a low-profile or protective setting.
Andrew's core palette
This is a comparison rather than a limit on what Andrew will use. His established coloured-stone work centres particularly on sapphire in its many colours, ruby, emerald, tsavorite and coloured diamonds, but he is very open to exploring other gemstones. The individual stone, the setting and the way the ring will be worn simply need to work well together.
Hardness is not toughness
Emerald scores reasonably well on Mohs, yet natural inclusions can make it more brittle than the number implies.
A protective setting and an honest understanding of everyday habits are as important as the colour of the stone itself.
Metal and colour
Which metal pairs best with your stone?
The right metal depends on the individual stone's shade, not simply its colour family. Gemstone, metal, skin tone and surrounding stones should make one another look more alive.
This is where Andrew's eye and experience matter. He will curate the relationship between those elements and help you make the final decision with confidence.
Platinum
Can give blue sapphire a crisp, cool clarity. Some pink and green stones need to be checked carefully against it to avoid looking flat.
18ct yellow gold
Often enriches emerald, tsavorite and warmer sapphires. Its warmth can bring depth and contrast to saturated colour.
18ct rose gold
Works beautifully with many blue, green and pink stones. The exact alloy tone should be judged against the individual gem.
Six distinct starting points
Which Andrew Geoghegan design suits your stone?
Some AG designs were built with coloured stones in mind. Others took on colour later and grew into it. Options not shown as standard on the site remain clearly marked as available on enquiry.
Graduated colour
Asteria
Asteria was designed during lockdown while Andrew and his family were waiting for their house in Portugal to be built. The brightness of that climate became a ring: a central circle with light radiating outward.
With a tsavorite centre, the richest green sits in the middle and the surrounding stones lighten in steps. Sapphire and ruby work especially well using the same graduating approach.
Chocolate diamond, pink sapphire and orange sapphire versions are possible but not currently shown as standard. Ask Andrew directly.
Cannelé has been part of Andrew's collection since 2013. It began as a diamond ring, with fine hand-finished flutings curving from the halo into the band and converging into one decisive point beneath the setting.
Sapphire, ruby, pink sapphire and chocolate diamond work beautifully as centre stones with a diamond halo. Emerald appears on Petite Cannelé and is available on the standard size by enquiry.
Versions of this ring with coloured halos are coming to the collection and are available on enquiry in the meantime.
Cannelé Twist is the natural next step from Cannelé. Larger halo stones surround the centre and the fluting motif becomes a twist, flowing down from the setting into a rounder, more substantial band.
It carries the same hidden sculptural detail as the original, with greater visual presence on the finger. The sapphire version shows how strongly the design holds saturated colour.
Satellite is a two-stone design, each gemstone held within its own halo and placed at a different size and level.
Two rubies or sapphires create a completely different rhythm from a single centre stone. The asymmetry gives the ring movement and an unmistakable presence. Emeralds, chocolate diamonds, coloured sapphires and other gemstones are also available. Simply enquire.
Clair de Lune uses a double halo, allowing colour to move outward in layers. Doré is one of the most captivating expressions of the design: a rich chocolate diamond sits at the centre, surrounded by orange and yellow diamonds that move through warm, golden tones.
The effect is not simply a coloured centre with a decorative edge. The whole ring becomes a composition of related shades, with each halo changing how the colour beside it is perceived. Rouge moves through ruby and pink sapphire; Azure through layers of blue sapphire. Doré shows the idea at its warmest and most atmospheric.
A coloured gemstone should not be judged by carat weight alone. Andrew looks first at the quality and character of its colour, then at cut, dimensions, durability and how it will sit within the chosen design. Two sapphires of the same weight, colour category and apparent specification can look completely different.
01Colour and saturation
02Cut and light return
03Dimensions and visible size
04Durability, inclusions and treatment
This is why clients are shown a considered selection rather than left to choose from generic online descriptions. Andrew works closely with trusted gem merchants and his UK workshop team to inspect and compare stones in order to present the best options. If the client discussions take place online, detailed photography and video allow Andrew to assist with the selection process and explain how each option will relate to the metal and setting. It is a collaborative, expert process that ensures the customer can proudly wear a stone they cherish.
Once you understand durability, colour and design, go with your gut. Notice what happens when you look at a particular gemstone. Does it hold your attention? That reaction tells you more than any trend report.
DesignerAndrew Geoghegan
ExperienceThree decades in fine jewellery
Core stonesSapphire, ruby, emerald, tsavorite and coloured diamonds
Featured designsAsteria, Cannelé, Cannelé Twist, Satellite, Clair de Lune and Chapiteau
Lead timeGenerally 4 to 6 weeks, made to order
CraftCreated in UK workshops by artisan goldsmiths and gemsetters
Useful answers
Frequently asked questions
What is the most durable coloured gemstone for an engagement ring?
Ruby and sapphire are the most durable coloured gemstones for daily wear, both rating 9 on the Mohs hardness scale. Coloured diamonds rate even higher, at 10. Softer stones such as emerald and tanzanite can still be worn every day, but suit a protective setting or a careful wearer.
Can a coloured stone engagement ring be made in platinum, yellow gold or rose gold?
Yes. AG's coloured stone designs are available in platinum, 18ct yellow gold and 18ct rose gold. Blue sapphire can suit all three, while Andrew often prefers green stones such as emerald and tsavorite in yellow or rose gold. The final choice should be made by viewing the actual gemstone against the metal.
Can I choose a coloured stone for a halo setting like Cannelé or Asteria?
Yes. Many of Andrew's established designs work particularly well with coloured centre stones. Some were conceived with colour as part of their design language; others, including Cannelé, began with diamonds and evolved naturally into coloured-stone versions. Options not shown as standard can be discussed with Andrew directly.
Are coloured gemstone engagement rings ethically sourced?
Documentation varies by stone. Some larger coloured gemstones carry an independent certificate, but for most coloured stones that kind of paperwork does not exist in the way it does for diamonds. Every gem merchant Andrew works with belongs to trade bodies that support ethical sourcing, and he is happy to discuss the origin of your chosen stone.
How long does a made-to-order coloured stone engagement ring take?
A made-to-order engagement ring generally takes 4 to 6 weeks, although more complex designs or harder-to-source stones can take longer. Andrew will confirm the timeline once the design and stone are agreed.
Can a coloured stone engagement ring be resized later?
Usually, yes, although how many sizes depends on the design. Our advice is to establish the correct size before the ring is made. There is almost always a solution if a ring needs adjusting later.
What is the difference between a natural and a lab-grown coloured gemstone?
A natural coloured gemstone forms inside the earth, while a lab-grown version forms under controlled laboratory conditions. Every gemstone Andrew Geoghegan sells is natural. Some are heat-treated to bring out a particular shade, which is standard practice across the gemstone trade and does not affect how the stone wears.
Why choose a coloured stone over a diamond for an engagement ring?
A coloured stone lets you express something a white diamond cannot. Colour carries meaning, reads differently on every wearer and can shape the entire ring. Durability varies by stone, so everyday suitability should be considered before deciding.
About the designer
Designed personally by Andrew
Andrew Geoghegan is a multi-award-winning British fine jewellery designer with three decades of experience. He designs all his jewellery and commissions in both the UK and Portugal.
The work itself is created in his UK workshops by artisan goldsmiths and gemsetters, working with carefully selected coloured gemstones, ethically sourced diamonds and precious metals. Some coloured gemstones may have accepted treatments such as heat treatment; where relevant, Andrew will explain what is known about the individual stone.
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