Four countries produce the majority of gem-quality rubies. Burma, and in particular the Mogok region, remains the undisputed historical benchmark for its intensely red, slightly violet rubies known as “pigeon blood.” Mozambique (the Montepuez mines, in operation since 2009) has become the second largest source worldwide, producing rubies with vivid, luminous tones. Sri Lanka yields lighter rubies, often tending toward pink, with a velvety brilliance. Thailand and Vietnam round out the principal sources. Bonnot Paris sources directly from Burma and Mozambique.

The Mogok valley has been producing rubies of unique character for over 800 years. The local geology (marble deposits) and the nature of the trace elements (high chromium concentration, low iron content) give Mogok rubies a particularly vivid, slightly violet red, with an intense fluorescence that amplifies their brilliance under natural light. This is what is known as “pigeon blood.” Production from Mogok is today marginal compared with Mozambique, making these stones a genuine collector’s rarity. A certified unheated Burmese ruby can command five to ten times the price of an equivalent stone from Mozambique.

“Pigeon blood” is a premium colour designation for a ruby of intense, slightly violet red at maximum saturation, evoking the colour of a drop of blood on a pigeon’s beak. It is a strict qualification awarded by leading gemological laboratories (SSEF, GRS, AGL, Gübelin) according to precise criteria: hue, saturation, tone and fluorescence. Not all Burmese rubies qualify — it is a standard reserved for a fraction of the finest stones. A certified pigeon blood ruby typically commands 30 to 100% more than a classic ruby of equivalent weight.

The price of a ruby varies considerably depending on origin, colour, clarity and treatment. Expect €1,000 to €3,000 per carat for a good-quality heated Mozambique ruby (1 carat), €3,000 to €10,000 per carat for a fine quality of 1 to 2 carats, and €10,000 to €50,000 per carat for a gem-quality unheated Burmese ruby. Unheated pigeon blood rubies above 3 carats regularly reach several hundred thousand euros per carat at auction — a 25-carat Burmese ruby sold for $30 million at Sotheby’s in 2015.

Absolutely. With a hardness of 9 on the Mohs scale (out of 10), the ruby offers the same exceptional resistance as the sapphire — the second hardest gemstone in the world after the diamond. It withstands everyday wear with no need for a protective setting. Symbolically, the ruby is the stone of passion, courage and absolute commitment — a powerful statement for a marriage proposal. Its rarity, greater than that of diamonds at equivalent quality, also makes it an excellent long-term investment to pass down through generations.

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Three elements provide certainty. A gemological certificate from a recognised independent laboratory (SSEF, GRS, GIA, AGL) attests to the stone’s natural origin, treatment and mineralogical identity. Examination under a x10 loupe reveals characteristic inclusions (needle-like rutile, or “silk,” and colour zoning) that are virtually absent in synthetic rubies. Purchasing from a trusted professional — a stone dealer or jeweller, ideally a member of a recognised trade body such as the ICA for coloured stones — remains the best guarantee. Be wary of rubies that are too transparent and too inexpensive; they are almost invariably synthetic or heavily treated.

Heating is a centuries-old treatment carried out at 1,200–1,800°C to intensify colour and improve the clarity of rubies. Around 95% of rubies on the market are heated — it is an internationally accepted standard. An unheated ruby (“no heat” or “NH” on the certificate) retains all its natural characteristics and commands 50% to five times more than equivalent heated stones — the premium being all the greater the finer the ruby. Bonnot Paris offers both options and does not sell any ruby treated with beryllium or lead glass, contested treatments that alter the structure of the stone.