Pigeon's blood and Burmese rubies

Two phrases carry more weight in the ruby trade than anything else, pigeon's blood and Burmese. Both are used accurately by some sellers and loosely by many others, and the gap between those two uses can be worth a great deal of money.

Here is what each term actually means, who gets to apply it, and the sourcing question that any serious buyer should be asking in 2026.

Where the colour comes from

Starting with the chemistry, because it explains why Burmese material earned its reputation.

Rubies are the red variety of corundum and contain chromium, and Geoscience Australia notes that a small amount of chromium produces pink, while a true ruby needs enough for a distinctly red or slightly purplish red colour.

Chromium does something beyond colour, though. It makes ruby fluoresce red under ultraviolet light, including the UV present in ordinary daylight. The practical effect is that a fluorescent ruby appears to glow from within rather than simply reflecting red.

Why iron is the spoiler

Iron suppresses that fluorescence. Rubies from sources with higher iron content, Thailand being the classic example, return a red that reads as darker and flatter, however fine the stone otherwise is.

Material from the Mogok region of Myanmar has been studied closely by the Swiss Gemmological Institute SSEF, and the reason Mogok acquired its reputation is low iron. Low iron allows strong fluorescence, strong fluorescence produces that distinctive glow, and the glow is what people mean when they talk about Burmese ruby.

Worth noting that this is a geological characteristic rather than a magic property of a border. Low-iron material from Mozambique can show the same effect, which has reshaped the market considerably in the last decade.

What pigeon's blood actually means

This is the term most often misused, and the history is genuinely interesting.

For most of its life, pigeon's blood was a poetic trade expression with no definition behind it. Any dealer could apply it to any red stone, and plenty did. It survived because it described something real that buyers recognised, a vivid red with strong fluorescence, even though nobody had written down what qualified.

That changed when the laboratories stepped in. SSEF and the Gubelin Gem Lab agreed to harmonise their standards for the colour terms pigeon blood red and royal blue, with the goal of standardising usage for the benefit of the international gemstone trade.

GRS also publishes its own criteria for the term. So there are now defined standards, applied by specific laboratories, with published criteria behind them.

The catch for buyers

The term is only meaningful when a laboratory that defines it has applied it to that specific stone and said so on a report. Pigeon's blood written on a price tag, in a listing or in an email means nothing at all. It is not a protected term and nobody is policing its use in the wider market.

So the question to ask is never whether a stone is pigeon's blood. It is which laboratory said so, and may I see the report.

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The sourcing question

This matters more than the colour terminology, and it is the part most sellers skip.

In April 2021 the US Treasury designated Myanma Gems Enterprise, the Burmese state-owned entity responsible for all gemstone activities in the country, noting that gemstones are a key economic resource for the Burmese military regime. MGE handles permitting, licensing, royalties and the organised emporiums through which gems are sold.

That is a serious finding and it has shaped the market. A buyer who cares where their stone came from needs to understand it.

What it means in practice

The sanctions are US measures and do not automatically determine what is lawful elsewhere, so this is not a simple matter of legality for an Australian buyer. It is a matter of due diligence and of what you are comfortable with.

Two things make the picture more workable than it first appears. Stones mined and exported well before the 2021 designation, including antique and estate pieces, sit in a different position from recently exported material. And Mozambique has emerged as a major source of fine ruby, including low-iron material that performs much like Mogok stones.

Our view is straightforward. Ask where the stone came from and when it left. A seller who cannot or will not tell you is telling you something. Our sourcing and selecting page sets out how we approach this, and our sustainable and ethical page covers the broader commitment.

Heat treatment and the unheated premium

The other major value lever, and another place where documentation is everything.

The overwhelming majority of ruby on the market has been heat treated to improve colour and clarity. This is routine, permanent, stable and entirely accepted, provided it is disclosed.

Unheated rubies of fine colour are genuinely rare and command a substantial premium, often multiples of the equivalent heated stone. Here is the thing to understand about that premium. It is paying for rarity and collectability, not for beauty. An unheated stone does not look better than a heated one of the same final appearance.

So if you are buying a ring to wear, a disclosed heated ruby of excellent colour is often the better purchase. If you are buying for rarity, unheated with a laboratory report is the category you want. Both are legitimate, and conflating them is how people overpay.

Reading a ruby properly

GIA notes that colour is the most significant factor in ruby value, that the finest stones are pure vibrant red to slightly purplish red, and that per-carat prices rise dramatically with size for better quality material.

The fifth row deserves a flag. Lead glass filled rubies are widely sold and are a genuinely different product, heavily fractured low-grade corundum with glass injected into the cracks. They are fragile, damaged by ordinary jewellery repair, and worth a small fraction of a conventional heated ruby. Disclosure is required, and the price should tell you.

Wearing one

The good news after all that caution is that ruby is an outstanding stone for daily wear.

Ruby is the red variety of corundum, which means 9 on the Mohs scale, excellent toughness and no cleavage plane. Short of diamond, there is very little better suited to an engagement ring that never comes off.

The care is simple. Warm soapy water and a soft brush. The exception is filled or heavily fractured material, which needs gentler handling, which is one more reason to know exactly what you have bought.

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Worth knowing

• Ruby is corundum coloured red by chromium.

• Too little chromium gives pink sapphire rather than ruby.

• Chromium also causes red fluorescence, which produces the glow.

• Iron suppresses fluorescence, which is why high-iron sources look flatter.

• Mogok material is prized because it is low in iron.

• Low-iron Mozambique material can show the same effect.

• Pigeon's blood was an undefined trade term for most of its history.

• SSEF and Gubelin agreed to harmonise the standard, and GRS publishes its own criteria.

• The term only means something on a report from a laboratory that defines it.

• The US Treasury designated Myanma Gems Enterprise in April 2021.

• Gemstones were identified as a key economic resource for the military regime.

• Ask where a stone came from and when it was exported.

• Most ruby is heat treated, which is routine and must be disclosed.

• The unheated premium buys rarity rather than better looks.

• Lead glass filled ruby is a different and much cheaper product.

A fine ruby with documented colour, disclosed treatment and a sourcing history somebody is willing to put in writing is one of the great things in jewellery, and it will outlast everyone reading this. The same stone with none of that paperwork is a gamble dressed up in good adjectives. Our certificates and appraisals page explains what should come with a stone, and our piece on ruby engagement rings covers the design side.