Sapphire colours: the complete shade guide
François Deprez5/8/2026
The Ruby Guide: Origins, Quality, Price & Expert Advice
François Deprez
June 15, 2026
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5 min read
Bonnot Paris · The Precious Stone Journal 2026
The Ruby: a complete guide — origins, quality, price and expert advice
Colour, origins, pigeon's blood, treatments and price per carat — everything you need to know before choosing a ruby, by our coloured stone dealers.
Of all coloured stones, the ruby is the most intense. Stone of blood, courage and passion, it is also, at equal quality, the rarest and most valuable of gems — ahead of sapphire, ahead of emerald, and ahead of white diamond.
As a coloured stone dealer and jeweller — and the only French house to be a member of the ICA (International Coloured Gemstone Association) — we select our rubies directly at source, from our offices in Sri Lanka and Bangkok. Here is our complete guide to understanding, evaluating and choosing a ruby with confidence — including how to avoid the many pitfalls particular to this stone.
01
At a glance
The rarest of precious stones
Ruby belongs to the corundum family, exactly like the sapphire: they are the same mineral species, distinguished only by colour. It reaches a hardness of 9 out of 10 on the Mohs scale. Its colour comes from chromium, which produces both the red and a remarkable fluorescence — that inner fire that ignites in sunlight and which no other red stone possesses. From rough gem to finished jewel, here are the two faces of ruby.
The stone
The 5-carat cushion
A deep, saturated red in a 5 ct Mozambique cushion. At this size, worldwide supply runs to mere dozens of stones a year: rarity pushes the price per carat into an entirely different category.
The creation
The Floral ring
The same red, set: a 1.50 ct unheated Mozambique oval, surrounded by diamonds in yellow gold. A one-of-a-kind piece imagined and crafted by hand in our atelier.
Our position
Burma or Mozambique, heated or unheated: there is no such thing as an objectively "best" ruby. The finest ruby is the one whose red speaks to you, seen in natural light rather than under the spotlights of a display case, which flatter everything. This guide gives you the tools to compare what is truly comparable — and to pay a fair price for every stone.
02
Essentials & meaning
Understanding the ruby in three minutes
The word "ruby" comes from the Latin ruber, meaning simply red. Mineralogically, it is a corundum — an aluminium oxide — whose colour is due to the presence of chromium. This point matters: the same mineral coloured by iron and titanium produces blue sapphire. A pink corundum sits at the boundary: depending on the intensity of the red and on the laboratory, it will be classified as a ruby or a pink sapphire — with a considerable difference in price as a result.
With a hardness of 9/10, the ruby is, alongside the sapphire, the most durable of all coloured stones. In practical terms: it will not scratch on contact with everyday objects, it withstands knocks and is unaffected by water — a decisive advantage for an engagement ring worn every day, far more so than an emerald, which is considerably more fragile.
One final figure to illustrate its rarity: in 2015, the Sunrise Ruby, a Burmese stone of 25.59 carats, sold at auction for more than 30 million dollars — over one million dollars per carat. No sapphire, no emerald has ever reached that level.
The meaning of the ruby
The ruby symbolises passion, courage, vitality and protection. The stone of blood and life in many cultures, it was worn by warriors, who saw in it a source of invulnerability, and by sovereigns, who read in it the mark of power. It is the birthstone of July and the gem of the 35th wedding anniversary, the ruby anniversary.
03
The geography of the ruby
The origins that make the difference
With rubies more than with any other coloured stone, origin leaves a recognisable signature — and weighs heavily in the value. Two sources dominate the market today, and they tell two very different stories.
Burma — Mogok
The legend
The Mogok Valley has been producing the world's most prized rubies for five centuries: a pure, vivid red with spectacular fluorescence, the very source of the expression "pigeon's blood". Historical production is now greatly reduced, making these collector's stones.
Mozambique — Montepuez
The modern benchmark
Discovered in the late 2000s, the Montepuez deposit reshaped the market: it now supplies the majority of gem-quality rubies, often unheated, with deep reds and a consistency that Burma can no longer provide. The finest balance of quality and availability on the market.
Sri Lanka — Ceylon
The luminous reds
The island produces lighter, more luminous rubies, often close to raspberry pink. Less sought-after than deep reds, they offer an excellent entry point and a beautiful brightness in smaller sizes.
Thailand, Madagascar & others
The complementary sources
Thailand yields darker reds, rich in iron and without fluorescence. Madagascar, Tanzania and Afghanistan round out the picture. Bangkok also remains the world's trading hub for rubies, through which most stones pass before cutting.
What is "pigeon's blood", really?
Pigeon blood designates a pure, deeply saturated red — free of any brown or orange cast — paired with strong fluorescence. It is the most coveted designation on the market, awarded by the leading laboratories — SSEF, GRS, Gübelin. Long reserved for Burmese stones, it is today also granted to certain rubies from Mozambique. This single mention on a certificate can double the price of a stone: which is precisely why one must know how to read it, rather than be caught off guard by it.
04
Evaluating a stone
The 4 criteria that determine the price
As with diamonds, the value of a ruby is read through a handful of key criteria. Unlike diamonds, however, colour overwhelms everything else here — and treatment comes a close second, well ahead of clarity.
01
Colour (the defining criterion)
Hue, tone and saturation. The ideal: a vivid, pure red free of any brown or orange cast, with fluorescence. A greyish or overly dark red can lose two-thirds of its value.
02
Treatment
With rubies, this is decisive. Between a certified unheated stone and a lead-glass filled one, the difference in value can be tenfold or more — yet to the untrained eye, the two are indistinguishable.
03
Clarity
Rubies almost always contain inclusions: rutile “silk”, which authenticates the stone and sustains its fluorescence. A perfectly clean ruby offered at a low price is a warning sign, not a good deal.
04
Weight (carat)
More than anywhere else, price escalates sharply with weight. Above 2 carats in gem quality, supply becomes truly scarce on the world market: a 5 ct ruby is worth far more than five times a 1 ct stone.
The Bonnot Paris approach
Every ruby we offer is accompanied by an independent laboratory certificate (SSEF, GRS, ICA, Bellerophon…) attesting to its origin, treatment and characteristics. Our direct sourcing, with no intermediary, ensures you receive the stone at its true market price.
05
Treatment
Heated, unheated… or a trap?
Heating is an age-old treatment, practised since antiquity at very high temperatures to intensify colour and improve transparency. The vast majority of rubies on the market are heated: it is an internationally accepted standard, stable over time, and entirely legitimate provided it is declared on the certificate.
An unheated ruby (“no heat” or “NH”) retains all its natural characteristics. Considerably rarer than its heated counterpart, it commands a significant premium — one that can multiply several times over in larger weights and finer colours. This is the segment on which we focus our selection.
The lead-glass trap — essential reading
This is the defining problem of the ruby market, and it has no equivalent among other precious stones. Lead-glass filling involves injecting the fractures of a very low-grade ruby with lead glass to give it the appearance of a fine stone. The result: a piece of jewellery sold for a few hundred euros that deteriorates on contact with a common household product, cannot withstand a jeweller’s torch during repair, and holds no resale value whatsoever. These stones flood online channels and tourist markets alike. The only reliable protection remains a certificate from an independent laboratory explicitly stating the treatment. Bonnot Paris does not sell any lead-glass filled ruby, nor any synthetic stone.
06
Budget
How much does a ruby cost?
The price of a ruby varies enormously depending on origin, colour, treatment and weight. Below are concrete benchmarks, expressed as price per carat for a fine-quality stone.
2 000 – 6 000 €
per carat · entry level
per carat · entry level
Certified heated ruby, good colour, approximately 1 carat.
The entry point into a true ruby, with no compromise on authenticity.
6 000 – 20 000 €
per carat · fine quality
per carat · fine quality
Unheated, 1 to 2 carats, vivid red with strong fluorescence.
The ideal balance for an exceptional engagement ring.
20 000 – 50 000 €+
per carat · gem quality
per carat · gem quality
Mozambique or Burma unheated, gem quality, larger carats.
A stone to treasure across generations — Burmese pigeon's blood is in a class of its own.
These ranges are indicative. More telling are four real stones from our selection and what they cost today — the clearest way to visualise the rarity curve.
| Stone | What defines it | Price |
|---|---|---|
| Oval 1.02 ct | Unheated A fully natural, certified carat. The finest rarity-to-budget ratio for a first red stone. | 6 720 € ≈ 6 590 € / ct |
| Oval 2.59 ct | Above 2 carats, supply collapses. A stone as much for the collector as for the jewel. | 37 296 € ≈ 14 400 € / ct |
| Mozambique 1.50 ct | Unheated The most sought-after size for an engagement ring, in the quality that justifies the unheated premium. | 29 376 € ≈ 19 580 € / ct |
| Mozambique 5 ct | A 5-carat cushion. At this level, every stone is a market event. | 118 368 € ≈ 23 670 € / ct |
The Bonnot Paris approach
Through our direct sourcing from our offices in Sri Lanka and Bangkok, you pay the true value of the stone — not the successive margins of three or four intermediaries. With rubies, where price disparities between supply chains are the most pronounced in all of fine jewellery, this makes all the difference. For any given budget, you gain access to a quality well beyond what traditional resellers can offer.
07
Not to be confused
Ruby or another red stone? The right instinct
Several red gemstones can be mistaken for ruby — the history of jewellery is full of crown "rubies" that were nothing of the sort. Some are beautiful stones in their own right, but none matches ruby's rarity or its fluorescence.
| Stone | What sets it apart | Hardness |
|---|---|---|
| Ruby | Corundum The noblest of reds, fluorescent, and unrivalled in rarity at larger sizes. | 9 / 10 |
| Red spinel | Long confused with ruby in crown jewels. Almost always natural and unheated, with a slightly softer red. A superb and more accessible alternative. | 8 / 10 |
| Garnet | A darker, denser red, often tinged with brown, without fluorescence. A fine stone, but without ruby's rarity. | 6.5 – 7.5 |
| Rubellite tourmaline | A raspberry pink-red, bright rather than deep. A colourful, luminous alternative at a considerably lower price. | 7 – 7.5 |
The pink-orange rarity
The padparadscha
The ruby's closest relative: same mineral species, but in a delicate and exceptionally rare pinkish-orange. For those who seek the nobility of this stone while stepping away from pure red — also available as a padparadscha sapphire engagement ring.
The modern shade
The teal sapphire
At the chromatic opposite of the ruby, the shade making waves in contemporary jewellery: a blue-green between ocean and lagoon, for an engagement that charts its own course.
08
The inspiration
The ruby as an engagement ring
The red of the ruby calls for settings that let it breathe. Here are two pieces from our ruby collection, and two directions for imagining your own, drawing from our bespoke creations.
The halo setting
Floral, ruby 1.50 ct
An unheated oval from Mozambique, encircled by a corolla of diamonds in yellow gold. The warm gold makes the red sing: the classic, unrivalled pairing for a ruby ring.
32,400 €
The budget benchmark
Floral, ruby 1.02 ct
The same design around a one-carat stone. A concrete benchmark for what a complete ruby ring — diamonds and gold included — truly costs.
10,080 €
01
The solitaire
The stone alone, in yellow gold or platinum. Nothing to distract from the red — the most demanding setting, as it forgives no shortcoming in colour.
02
The diamond halo
A corolla of diamonds that amplifies the centre stone and makes the ruby appear larger. The most sought-after style for stones between one and two carats.
03
The toi et moi
A ruby alongside a diamond, or a ruby alongside a sapphire. The most symbolic setting for an engagement ring, and the most open to personalisation.
04
Yellow gold
With a ruby more than with any other stone, yellow gold warms and deepens the red, where platinum can harden it. A choice of metal that is never neutral.
Bespoke
Each of our rings is a unique piece, set around a stone sourced directly by us. You may draw inspiration from an existing design to imagine your own: we transpose its spirit without ever reproducing it identically. Discover bespoke creation →
09
Frequently asked questions
Everything you may wonder about the ruby
What is a ruby?
It is the red variety of the same mineral species as the sapphire: colour alone sets the two apart. Its hue comes from chromium, which also gives it its characteristic fluorescence. With a hardness of 9/10, it ranks among the most durable stones in existence, second only to the diamond — and among the rarest in gem quality.
What does the ruby symbolise?
It embodies passion, courage, vitality and protection. Its name derives from the Latin ruber, meaning red. Regarded across many cultures as the stone of blood and life, it has been worn by warriors and sovereigns alike. It is the birthstone for July and the gemstone of the 35th wedding anniversary.
Where do the finest rubies come from?
Burma, and its Mogok Valley, remains the historic benchmark for pigeon's blood. Mozambique, with the Montepuez deposit, has become the world's leading supplier of gem-quality material, often in unheated stones. Sri Lanka, Thailand and Madagascar complete the picture. Bonnot Paris sources directly through its offices in Sri Lanka and Bangkok.
What is a "pigeon's blood" ruby?
It is the most sought-after designation on the market: a pure, vivid, deeply saturated red with no brown or orange undertone, accompanied by strong fluorescence. It is awarded by the leading laboratories (SSEF, GRS, Gübelin), historically to Burmese stones and today to certain Mozambican rubies as well. Its presence on a certificate can double the price of a stone.
How much does a ruby cost?
Expect roughly €2,000 to €6,000 per carat for a good-quality heated ruby (~1 ct), €6,000 to €20,000 per carat for a fine unheated stone of 1 to 2 carats, and €20,000 to upwards of €50,000 per carat at gem quality. In practice, an unheated oval of 1.02 ct is priced at around €6,700, while a Mozambican cushion of 5 ct exceeds €118,000.
How do you avoid a lead-glass-filled ruby?
These very low-quality stones, whose fractures are filled with lead glass, are fragile, deteriorate on contact with household products and hold no resale value. The only reliable safeguard is a certificate from an independent laboratory that explicitly states the treatment. Bonnot Paris does not carry any such stones, nor any synthetic ones.
Ready to choose your ruby?
Meet our experts to explore a selection of certified rubies from Burma and Mozambique, sourced directly — or imagine with us a creation made entirely to your measure.
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François Deprez
Founder of Bonnot Paris
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