Gemstones Guide

Gemstone engagement rings aren’t the alternative to a diamond. For some people they’re the first choice, decided long before the conversation about settings or budgets begins. For others, sapphire engagement rings enter the picture after weeks of diamond research, when something shifts. Both are valid starting points for a good ring.

What makes colored stone buying different from diamond buying is that the category is significantly less standardised. The supply chain is more fragmented, certification is less consistent, and quality variation within any single species is enormous. A blue sapphire and a teal sapphire are both sapphires. Their value, character, and availability are completely different conversations. That’s what this guide is for.

Start With What You Actually Want

The best colored stone engagement rings start with a genuine resonance with a color, a stone, or a feeling, not with what’s appearing in feed right now. Trends in colored stones move faster than diamond trends, partly because the category is more visual and partly because a single high-profile ring can shift search behaviour overnight.

The ring that holds up over a decade is the one chosen because the color genuinely means something to the person wearing it. The teal sapphire chosen because the client has loved that particular shade since she was a child is a different ring from a teal sapphire chosen because teal is having a moment. Both can be beautiful. Only one is hers.

The practical version of this advice: if you’re considering a colored stone, spend some time with references before you come in. Color is personal and almost impossible to describe precisely. A photo of a stone that stops you tells us more than any description. Bring what you’ve saved, and we’ll go from there.

Hardness and Daily Wear

The most practically important question for any engagement ring stone is how it holds up to daily wear. Not every stone that’s beautiful is appropriate for a ring that never comes off, and knowing the difference before you fall in love with something prevents disappointment.

The Mohs scale measures scratch resistance on a scale of 1 to 10. A diamond is 10. But the scale isn’t linear; diamond is significantly harder than anything below it, and the practical difference between a 9 and an 8.5 matters less than the difference between a 7.5 and a 9. Everyday dust contains quartz particles, which sit at 7 on the Mohs scale. Any stone below 7 will scratch with regular wear.

Sapphire and Ruby (Mohs 9)

Both are corundum: the same mineral family, different trace elements producing different colors. At Mohs 9, they’re the most durable colored stones available for daily wear, and the standard recommendation for someone who wants to forget their ring is on. Ruby and sapphire in every color: blue, teal, green, pink, yellow, padparadscha, all share this durability. It’s one of the reasons sapphire dominates the colored stone engagement ring category.

Alexandrite (Mohs 8.5)

Exceptional hardness and the most remarkable optical phenomenon in the gemstone world- green in daylight, shifting to red-purple under incandescent light. Fine natural alexandrite is genuinely rare and priced accordingly. Lab-created alexandrite delivers the color-change effect at a fraction of the cost and is an excellent option for someone drawn to something truly distinctive.

Emerald (Mohs 7.5–8)

The most requested colored stone after sapphire, and the one that requires the most honest conversation before purchase. Almost all natural emeralds are treated- oils or resins filling the surface-reaching fractures that are characteristic of the species. The industry term ‘jardin’ (French for garden) describes the internal fracture patterns that are considered normal rather than defects. An emerald requires more mindful handling than a sapphire and is better suited to a ring worn for occasions than one worn daily without thought. For someone who loves the color and understands the care, emerald engagement rings are a beautiful and considered choice.

Morganite (Mohs 7.5–8)

A soft peachy-pink beryl that photographs beautifully and pairs particularly well with rose gold. Requires more careful daily wear than sapphire. The color can fade with prolonged UV exposure over years. Worth knowing upfront.

Aquamarine (Mohs 7.5–8)

A blue-to-teal beryl, typically with excellent clarity and a clean, modern character. More durable than it looks given its clarity, but still requires the same mindful approach as emerald for daily wear.

For recommendations on how to care for colored stones, visit our Jewelry Care Guide.

Sapphires: The Full Picture

Blue is the first color most people think of when they hear sapphire. It’s also one of the most variable. The range runs from pale ice blue through mid-blue cornflower tones to the deep, almost inky blues of fine Ceylon material. Beyond blue, sapphires come in every color: teal, green, yellow, pink, peach, and the rare padparadscha, an orange-pink shade that commands significant premiums. The only color sapphires don’t come in is red- red corundum is ruby.

Right now, the colors we see most often in consultations are blue, teal, green, and pink. Teal and green sapphires in particular have had significant attention recently; their blue-green depth reads differently from a traditional blue, and they suit a wider range of skin tones and settings. None of that makes them more or less the right choice. It’s worth knowing what’s driving the search so you can separate interest from resonance.

What Makes a Sapphire Good

The color sweet spot is clear, well-saturated, and not so dark that the stone loses brilliance. A sapphire that looks rich in a jeweller’s light but closes to near-black outdoors has too much tone. A sapphire that looks washed out in sunlight lacks saturation. The ideal is a stone that reads the same color across lighting conditions: rich without being heavy, vivid without being thin.

Cut matters significantly for sapphires and is underappreciated by most buyers. Unlike diamonds, where the GIA grades cut on a formal scale, colored stones are cut by eye and intuition, and quality varies widely. A well-cut sapphire distributes color evenly across the face of the stone. A poorly cut one shows color concentrated at the edges with a pale or windowed centre, a phenomenon called extinction. Seeing the stone in person, in multiple light sources, is the only reliable way to assess cut quality in a colored stone.

Any natural sapphire, regardless of color or origin, is rarer than a lab-grown diamond. It formed under natural conditions that cannot be rushed or replicated at scale in the same way. That rarity is part of what the colored stone category offers that diamond cannot.

Heat Treatment

Most sapphires on the market are heat-treated: a process that improves color and clarity by exposing the rough stone to high temperatures before cutting. Heat treatment is standard, accepted, and should always be disclosed. An unheated sapphire of equivalent appearance commands a meaningful premium because of its rarity, and treatment status appears on GIA and other major lab certificates.

Origin

Kashmir, Burmese, and Ceylon (Sri Lankan) sapphires carry origin premiums that reflect historical rarity and quality associations. Madagascar and Australian sapphires offer strong quality at more accessible price points. Origin matters most for buyers who value provenance specifically, and matters less when the color and quality are the primary criteria.

The oval cut is our most requested shape for sapphires by a significant margin. An oval maximises face-up color, suits the elongated proportions that most clients are drawn to, and works across a wide range of setting styles. That said, shape is personal. What matters is that the proportions of the oval read well. A wider oval reads more cushion-like; a more elongated oval reads more classically. It’s worth seeing a few before deciding.

Stone by Stone

Each colored stone has its own character and its own considerations. Here’s what’s worth knowing before the consultation.

Ruby

The rarest of the corundum family at genuine quality. A fine ruby, a vivid red, strongly saturated, without heavy treatment, commands prices that exceed equivalent-quality diamonds at significant carats. Most rubies on the market are heavily treated, and a ruby at an accessible price point almost certainly reflects significant heat treatment, fracture filling, or both. Worth being direct about: a fine ruby is not an affordable alternative to a sapphire. It’s a different category entirely.

Emerald

The treatment reality is the most important thing to understand about emeralds. Almost all natural emeralds are oiled or resin-filled to improve clarity. This is industry standard and is disclosed on certificates. A completely untreated emerald of significant quality is genuinely rare and priced accordingly. Colombian emeralds are the standard reference for quality; Zambian emeralds offer a slightly deeper, bluer tone that some prefer. Both are beautiful. The honest recommendation: if you love emeralds and understand the care they require, a good emerald is a meaningful choice. If you want a green stone you never have to think about, a green sapphire is the more practical option.

Alexandrite

The color-change phenomenon- green in natural daylight, shifting to red or purple under incandescent light- is caused by the stone’s unusual absorption of light across the visible spectrum. Fine natural alexandrite is one of the rarest gemstones in the world. Lab-created alexandrite produces the same optical effect and is an honest and excellent alternative. Worth considering for anyone who wants something genuinely unlike anything else.

Morganite

A peachy-pink beryl with excellent brilliance and a soft, romantic character. It photographs beautifully, which is part of why it’s widely searched. The limitations are real: hardness at 7.5-8 means more mindful care than sapphire, and the color can lighten with sustained UV exposure over years. Worth knowing before choosing it as a daily wear ring.

Colored Diamonds

Fancy colored diamonds: yellows, pinks, blues, and greens, are the rarest and most expensive stones in the diamond world at significant saturation. Natural fancy colored diamonds at meaningful color intensity are priced beyond most engagement ring budgets. Lab-grown colored diamonds deliver the color at a fraction of the cost and have driven significant interest recently. Our clientele have particularly shown interest in pink, blue, and green. If color is the priority and origin is secondary, lab-grown colored diamonds are worth considering.

Settings for Colored Stones

The setting affects both how a colored stone looks and how protected it is, and the calculus is different from diamond settings because color and durability vary more across the colored stone category.

Bezel Settings

The metal wraps around the girdle of the stone, providing maximum protection. Particularly useful for emeralds and stones with durability concerns. A bezel-set stone reads more modern and architectural than a prong-set one, which works beautifully for teal or green sapphires where the setting character is part of the aesthetic.

Prong Settings

Maximum light exposure, maximum stone visibility. The right choice for sapphires and rubies where durability isn’t a concern. A four-prong or six-prong setting lets color read all the way to the girdle of the stone rather than having the metal interrupt it.

Halo Settings

A ring of smaller diamonds around the colored centre stone. Increases apparent size and adds diamond brilliance alongside the color. A strong choice for someone who wants the colored stone as the primary element but doesn’t want to give up diamond presence entirely. 

Metal Color and Stone Color

Yellow gold warms a cool stone. A teal sapphire in yellow gold reads differently from the same stone in platinum; the gold pushes the teal slightly warmer, toward green. White metals keep the color reading truer. Rose gold and pink or peach stones is an obvious pairing. There’s no wrong answer, but it’s a decision worth making deliberately rather than defaulting to whatever the setting comes in.

The consultation is where these decisions come together. One of the most useful things we do is show clients the same stone in different settings and metals before any commitment is made. The stone often chooses its own setting once you see it in context.

Planning an engagement ring? Visit our Engagement Ring Style Guide for helpful tips on how to craft your perfect design.

Certification and Sourcing

Colored stone buying is harder than diamond buying in one important way: there is no universal grading scale. A GIA diamond certificate is globally comparable. A colored stone certificate describes the specific stone but cannot be benchmarked against a universal grade the way diamond color and clarity can. ‘Vivid’ on one laboratory’s certificate is not the same as ‘vivid’ on another’s.

Which Certificates Matter

GIA certifies colored stones and provides origin determination and treatment disclosure. The Gübelin Gem Lab and SSEF in Switzerland are the international standards for high-value colored stones, particularly important for rubies, sapphires, and emeralds where origin significantly affects price. For a significant purchase, a certificate from one of these labs is worth requesting.

Treatment Disclosure

Heat treatment of sapphires and rubies is standard industry practice and should always be disclosed. Fracture filling of emeralds is equally standard. What matters is disclosure, not the treatment. A stone represented as unheated that has been treated is a misrepresentation, and origin premiums are built on that transparency. Always ask.

How We Source

Our colored stone sourcing works differently from our diamond sourcing because the market is structured differently. We maintain direct relationships with suppliers built over decades, which means access to stones that aren’t sitting in a standard wholesale inventory. When a client comes in with a specific brief: a color, a size, a shape, a budget- we can search across those relationships rather than being limited to what’s on a shelf.

We carry a curated selection of colored stones in the studio. If the stone you’re looking for isn’t in it, we can source most colored stones globally. We need three things to start: color direction, approximate carat size, and budget.

Want to learn more about how we source stones and what that means for you? Visit Sourcing with Integrity.

Budget for Colored Stones

Colored stone pricing is less transparent than diamond pricing because there’s no public equivalent to the diamond price lists that dealers reference. Quality variation within a species is enormous, and a slight difference in color saturation, treatment status, or origin can represent a significant difference in price. Two oval sapphires of the same carat weight can differ by thousands of dollars.

The most useful thing to bring to a colored stone consultation is a clear color direction and a budget range. Not an exact number, but a range. That’s enough for us to show you what’s possible and have a conversation about tradeoffs between size, color quality, and origin.

Lab-grown sapphires, rubies, and emeralds exist and are optically identical to their natural counterparts. They’re significantly less expensive. For someone whose priority is the color and not the rarity or natural origin, they’re worth considering.

 

Care and Storage

Colored stones don’t all care for themselves the same way. Here’s the short version of what matters.

Sapphires and rubies are the most forgiving. Both can be cleaned with warm soapy water and a soft brush, and both can go in an ultrasonic cleaner at a professional level without concern. Emeralds cannot- the vibration disrupts the oil treatment and can worsen existing fractures. Emeralds should be cleaned gently by hand with mild soap and water only.

Store colored stones separately from each other and from diamonds. A sapphire at Mohs 9 will scratch a morganite at Mohs 7.5. A diamond will scratch everything below it. Individual fabric-lined pouches or a divided jewelry box prevents that accumulation of surface damage that isn’t visible until you look closely under a loupe.

Keep emeralds away from ultrasonic cleaners, steam, and cleaning products. The same applies to alexandrite and aquamarine. When in doubt, bring the piece in; we can clean it properly and check the setting at the same time.

Color is the one thing you have to see in person.

A screen can’t show you how a teal sapphire shifts in different light. It can’t show you how a stone that looked right in a photo reads on your hand. Come in and see what we have. If your stone isn’t in our collection, bring a color reference and we’ll find it.