TL;DR
Sapphires, rubies, and emeralds are the three most-used coloured gemstones in fine jewellery. Sapphire (Mohs 9) is the toughest and comes in nearly every colour, not just blue. Ruby (Mohs 9) is the red variety of corundum and is almost always heat-treated — that's normal, not a flaw. Emerald (Mohs 7.5–8) is more fragile and is almost always oil-treated to clarify its colour, so it needs special care. In Montreal, expect a small jewellery-grade sapphire to start around $800 CAD, with engagement-grade centre stones running from $3,000 CAD to $25,000 CAD and up.
Table of contents
- Why choose a coloured stone
- Sapphire — the most versatile
- Ruby — rare, and yes, treated
- Emerald — beautiful but demanding
- Origin, treatments, and certificates
- What it actually costs
- Coloured stone vs diamond — how to choose
- Birthstones and sensitive skin
- FAQ
Why choose a coloured stone
A coloured stone changes the whole tone of a piece. Where a diamond plays with light, a blue sapphire, a ruby, or an emerald plays with colour. It's more personal, often more distinctive, and — depending on the stone — sometimes more affordable than a comparable diamond.
At Bijouterie Jamil's bench in Montreal, three reasons keep coming up: someone wants their birthstone, someone wants an engagement ring that doesn't look like everyone else's, and someone inherited a stone and wants it reset. All three are good reasons. But each stone has its own rules, and that's what we'll cover here.
Quick note on terms: "precious stone" is an old word. The modern technical term is coloured stone, which covers corundum (sapphire and ruby), beryls (emerald, aquamarine), garnets, tourmalines, and so on. We'll focus here on the three pillars — sapphire, ruby, emerald — because those are the ones you ask about most.
Sapphire — the most versatile
What it is
Sapphire is a variety of corundum, the same mineral as ruby. It scores 9 on the Mohs hardness scale, just below diamond (10). In plain terms: a sapphire stands up to daily wear better than almost any other coloured gem. It's our first recommendation when a client wants a coloured engagement ring they'll wear every day.
Every colour, not just blue
Most people picture blue when you say sapphire. But sapphire comes in pink, yellow, green, purple, orange, even colourless. Pink sapphire and the orange-pink padparadscha sapphire have been in heavy demand for the last few years. If a particular colour appeals to you but you want corundum durability, ask whether it exists in sapphire — usually, it does.
Origin
Origin matters at the high end. Sapphires from Kashmir and Burma (Myanmar) are historically the most sought-after, followed by Sri Lanka (Ceylon) and Madagascar. Australia produces a lot of darker, more affordable blue sapphires. For most buyers, origin matters less than colour, clarity, and cut. For an investment-grade stone over $10,000 CAD, ask for an independent certificate that names the probable origin.
Treatment
More than 90% of commercial sapphires are heated to stabilize and improve colour. This isn't a flaw. It's the standard the GIA and global trade accept. An unheated sapphire of fine colour costs significantly more — that's an investment decision, not an aesthetic one.
Ruby — rare, and yes, treated
What it is
Ruby is the red variety of corundum. To be called a ruby instead of a pink sapphire, the colour has to fall in the red range — from pinkish-red to "pigeon's blood" red. Below that saturation, the stone is technically a pink sapphire. It's a fine line, but it changes the price tag.
Why ruby is expensive
Fine-quality ruby is one of the rarest stones in the world. An untreated 2-carat Burmese ruby with good colour can outprice a diamond of the same size. For most of us, we're really talking about East African rubies (mainly from Mozambique), heat-treated, which give beautiful red colour at a much more accessible price point.
Treatment, again
Almost every ruby on the market is heated. Some get an additional lead-glass filling treatment to mask fractures — that one is more controversial and absolutely must be disclosed, because it makes the stone fragile and sensitive to ultrasonics and household chemicals. When you're shopping a ruby, always ask what kind of treatment was done. At Bijouterie Jamil, we tell you before you ask.
Durability
Like sapphire, ruby sits at 9 on Mohs. It's an excellent everyday stone — provided it isn't lead-glass filled.
Emerald — beautiful but demanding
What it is
Emerald is the green variety of beryl. Its hardness is 7.5 to 8 on Mohs — still solid, but not in the same league as corundum. More importantly, almost every natural emerald contains internal inclusions that the trade calls a jardin (garden). That's expected, not a defect.
Oiling is normal
Because of those inclusions, more than 95% of emeralds are oil-treated with cedar oil or a clear resin to improve apparent clarity. This is globally accepted. But it changes how you have to care for the stone:
- No ultrasonic cleaning
- No steam cleaner
- No household chemicals
- Warm soapy water and a soft brush — that's it
- Periodic re-oiling at your jeweller, roughly every 5 to 10 years depending on wear
In Montreal, dry winter air can speed up oil evaporation. If your emerald starts to look milky, bring it in — we'll inspect and re-oil if needed.
When emerald is the right choice
For earrings, a pendant, or a cocktail ring worn occasionally, emerald is gorgeous and reasonably accessible. For an engagement ring worn 24/7, we'll have an honest conversation: it's possible, but you have to accept the extra care and a setting that protects the stone properly.
Origin, treatments, and certificates
Three questions to always ask before buying a coloured stone over $1,500 CAD:
- What's the origin? Not always determinable, but often yes.
- What treatments were applied? Heat only? Fracture filling? Oiling? Diffusion?
- Is there an independent certificate? For stones over $3,000 CAD, we recommend a report from GIA, Gübelin, or SSEF. These labs disclose probable origin and detected treatments.
An honest seller will give you all three answers without stalling. If they hesitate, walk. For more on certificates in fine jewellery, see our guide to diamond certification — the same transparency principles apply.
What it actually costs
Realistic ranges in Canadian dollars, in Montreal, in 2026, for a stone set in a simple 14K gold ring:
| Stone | Small (0.5–1 ct) | Medium (1–2 ct) | Centre stone (2 ct +) |
|---|---|---|---|
| Heated blue sapphire | $800 – $2,500 | $2,500 – $8,000 | $8,000 – $30,000 + |
| Unheated fine-colour sapphire | $3,000 – $8,000 | $8,000 – $25,000 | $25,000 – $100,000 + |
| Heated Mozambique ruby | $1,500 – $4,000 | $4,000 – $15,000 | $15,000 – $50,000 + |
| Zambian / Colombian emerald | $1,000 – $3,500 | $3,500 – $12,000 | $12,000 – $60,000 + |
These ranges exclude GST and QST. They assume a clean cut and honest colour — not museum quality, not bargain-bin either. For a precise quote, we do free in-store appraisals and quotes.
Coloured stone vs diamond — how to choose
A simple framework:
- You want maximum durability and classic white sparkle → diamond or white sapphire
- You want a signature colour, worn daily → sapphire (any colour) or heat-only ruby
- You want dramatic colour, worn occasionally → emerald, tourmaline, tanzanite
- Tight budget, want size → Australian blue sapphire, garnet, topaz
- Investment piece → unheated Kashmir or Burma sapphire, unheated Burmese ruby, Colombian "muzo" emerald
For most of the coloured engagement rings we build to order, sapphire wins. It's tough, available in every colour, and its price is more stable than top-grade ruby or emerald. If you want to compare against a diamond centre stone first, see our engagement ring buying guide.
Birthstones and sensitive skin
Birthstones — short version
- Sapphire — September
- Ruby — July
- Emerald — May
It's a nice reason to give a piece of jewellery. But don't sacrifice durability for a calendar — if the recipient is a May baby but won't baby an emerald, a green sapphire is an excellent compromise.
Allergies and sensitive skin
The stones themselves almost never cause allergies — they're inert minerals. The reaction almost always comes from the metal. If you've reacted to cheap white gold or fashion jewellery, the culprit is usually nickel in the alloy.
For sensitive skin, we recommend: - 14K or 18K yellow or rose gold — naturally very low-reactive - 950 platinum — the gold standard for hypoallergenic, ideal for engagement rings - Nickel-free white gold (palladium-alloyed) — we order this on request
At our bench, we always specify the alloy we use, and we can build a ring entirely nickel-free. If you've ever had a reaction to jewellery, tell us before we start — that's important information, not an awkward question.
CTA
Trying to choose between sapphire, ruby, emerald, or diamond? Stop by Bijouterie Jamil in the heart of Montreal. We'll pull out several stones, walk you through the treatments, and give you an honest quote — no pressure. Book a free consultation or send us your question.
FAQ
Is sapphire really always blue? No. Sapphire comes in pink, yellow, green, purple, orange, colourless, and even black. Blue is just the best-known colour. Any corundum that isn't red is technically a sapphire.
Why is every ruby heat-treated? Because heating improves and stabilizes the stone's natural colour, and it's been an accepted practice in the global trade for centuries. An unheated ruby with fine colour is extremely rare and costs many times more. Heat treatment alone is considered normal; lead-glass filling is a separate, more invasive treatment that must always be disclosed.
Can an emerald handle daily wear? With care, yes. It's softer than sapphire or ruby (Mohs 7.5–8) and most emeralds are oil-treated, so it won't tolerate ultrasonics, steam, or sharp impacts. For an everyday ring, a protective setting (halo or bezel) and periodic re-oiling make the stone viable.
Can a coloured gemstone replace a diamond as an engagement ring? Yes, and it's increasingly popular in Montreal. Sapphire is our first recommendation for that use because it's almost as hard as diamond. Ruby works too. Emerald requires an honest conversation about care.
How do I know if a stone has been treated? Ask the seller, and require an independent certificate for any stone over $3,000 CAD. Labs like GIA, Gübelin, and SSEF test for and disclose detected treatments.
Why does cheap jewellery make me itch? It's almost never the stone. It's the metal — usually nickel in a low-grade white gold alloy or a plating that's wearing off. A ring in 14K or 18K yellow gold, rose gold, or platinum should not cause a reaction. If your skin is highly sensitive, ask explicitly for a nickel-free alloy.
How much does a sapphire engagement ring cost in Montreal? A simple 14K gold ring with a roughly 1-carat heated blue sapphire typically lands between $2,500 and $6,000 CAD before taxes. Add accent diamonds or step up the sapphire's quality and the price climbs from there.
What's the difference between a natural sapphire and a synthetic sapphire? A synthetic (lab-grown) sapphire has the same chemistry and hardness as a natural one but costs a fraction of the price. For everyday wear it's a valid option, as long as it's disclosed. We always identify it clearly — a synthetic sapphire isn't a natural sapphire, and the price tag has to reflect that.
About the author
Nader Khazzoum is master jeweller and co-owner of Bijouterie Jamil in Montreal. A specialist in custom fabrication, stone setting, and laser welding, he has been setting sapphires, rubies, and emeralds at the bench for more than 25 years. To book a consultation, reach us through bjamil.com.
