All you need to know about the regal red—and super rare—stone.
RUBIES
Tradition has it that when Queen Elizabeth II opens Parliament, she wears the Imperial State Crown. Lately, however, the crown sits next to her on a cushion as if it were one of her beloved dogs. Studded with over 3,000 gemstones, it weighs just over a kilogram, which is a lot to wear on your head when you have to deliver a speech—especially when you’re 94. Among the multitude of diamonds and precious baubles on the crown is a chunky cabochon called the Black Prince’s Ruby. It sits dead centre, right above the Cullinan II diamond. The name of this egg-shaped gem comes from one of its early owners, Edward of Woodstock, otherwise known as the Black Prince. The legendary stone kept Henry V company at Agincourt, and it showed up on Richard III’s helmet at the Battle of Bosworth. The story of this crown jewel is not just great history; it’s a cautionary tale for anyone thinking of buying a ruby. The other name for a stone like the Black Prince’s Ruby is the Great Impostor. That’s because that big hunk of uncut red rock on the Queen’s crown is not a ruby at all but a spinel. Rubies are extraordinarily rare gemstones—rarer than diamonds—but spinels are even rarer. Even so, spinels don’t carry the same per-carat value as rubies (according to the Gemological Institute of America, a high-quality spinel may sell for around 10 per cent of the value of a ruby of the same quality), and until the late 19th century, it was nearly impossible to tell the two apart.
WHAT EXACTLY ARE RUBIES?
Geologically, rubies, like sapphires, are part of the corundum mineral family. They get their juicy cranberry colour from a trace element called chromium. The best rubies can be found nestled in marble and are a glorious, glowing crimson because marble contains little iron. Rubies that form in basalt rock, however, usually have a darker hue because basalt has quite a lot of iron.
Coloured gemstones have been having a heyday over the past few years, and rubies are, as they are called in Sanskrit, ratnaraj, or “king of the gems.” Rubies have long been a royal favourite because they have everything going for them: They’re the colour of passion, they’re as hard as nails (and almost as hard as diamonds, at 9 on the Mohs scale) and they’re incredibly valuable. Plus, they go perfectly with the red carpet at awards events: Chopard capitalizes on this with its annual Red Carpet Collection, which often features stunning ruby pieces.
RUBIES VS. SPINELS VS. RUBELLITES VS. GARNETS
Rubies are very tricky to buy, due to the various other red stones they can be confused with. Rubellites are not as hard as rubies—and garnets lesser still. One way to tell a rubellite from a ruby is that rubellites become electrically charged when heated up. In general, however, shining a light through the stones will give you the most information about which is which. When you shine a light through a ruby, the beam splits in half (also known as double refraction), which results in the ruby appearing to be two different colours: One is orangey red, while the
other is more of a violet red. And to make things more complicated, there is another angle at which the ruby appears as one solid colour, not two, so you should test the stone at different angles. When you shine a light through a garnet or a spinel, however, it appears as a single colour at every angle.
FAKES ETC.
Besides the plethora of non-ruby red stones to confuse us, there is the matter of synthetic rubies, as well as rubies that have been dyed, filled or diffusion-treated to appear flawless and radiant red. A reputable jeweller can be relied upon not to sell you a phony ruby or a real one that’s been treated without telling you. If you have doubts, look to see if your jeweller or dealer is a member of the American Gem Trade Association, the International Colored Gemstone Association and/or The World Jewellery Confederation.
Rubies were the first gemstone to be grown in a lab—by French chemist Auguste Verneuil in the late 1800s. Aside from lab-grown rubies, there are rubies that have been tinkered with to look more beautiful, something that is very widespread. Some are dyed to attain a more intense red, while others are filled with molten lead glass, oil, resin or wax to smooth over fractures to make the stones look more translucent or simply feel heavier. A gemologist will be able to detect these treatments.
One treatment that is difficult to detect is lattice diffusion—a process in which an element is diffused, using heat and chemicals, into a gemstone’s atomic lattice to enrich its colour. In the 1980s, experts experimented with titanium and chromium diffusion, but these elements weren’t able to fully penetrate the stone with colour. It wasn’t until the early 2000s that beryllium-diffused gemstones—which were strongly coloured—came onto the market. A qualified laboratory will be able to detect this treatment.
WHERE DO THEY COME FROM?
Rubies typically come from Southeast Asia, the Himalayas and East Africa. But if it is a gorgeous “pigeon’s blood”-red Burmese ruby from the Mogok valley in Myanmar (formerly Burma), you might want to think again. Celebrated stones like this likely come from mining companies whose profits go to Myanmar’s military. Earlier this year, the United Nations’s International Court of Justice ordered the country to protect the Rohingya—a Muslim minority group— from genocide.
To confuse matters further, most rubies from Myanmar are reportedly processed through Thailand and Hong Kong to mislead gem dealers and customers: The fiery-ruby ring you’re lusting after could very well be a “genocide gem.” Mozambique is also a major supplier of beautiful rubies—the Montepuez mine was discovered in 2009. But here, too, there have been recent reports of violence and the abuse of local artisanal miners.
A new initiative may clarify if a coloured stone has been sustainably sourced and processed or not. Switzerland’s Gübelin Gem Lab recently released its Provenance Proof Blockchain, a secure digital logbook that traces each stone from the mine to your jewellery box. Time will tell if this blockchain technology ensures complete traceability, but if it works, it could make the coloured-gemstone trade as transparent as the ruby you’ve got your eye on.