Smooth-domed rubies set in a row in 1966, when Scandinavian goldsmiths let colour do the talking. A ruby cabochon bracelet in 18K gold.
The ruby is the red variety of the mineral corundum - the exact same mineral as sapphire, coloured red by a trace of chromium - and for most of recorded history it was the most valuable gemstone on earth, prized above diamonds. Fine natural rubies of real size are genuinely rarer than fine diamonds, and in antique jewelry the ruby has always meant one thing: passion, worn openly.
What makes a ruby good
Colour is nearly everything. The ideal is a pure, vivid red with just a whisper of blue - the shade the trade calls pigeon blood. Stones lean from pinkish red toward brownish red, and the closer to that pure vivid centre, the more valuable the stone. Historically the most celebrated rubies came from Burma, while Thai stones run darker and garnet-like.
Clarity is judged gently. Rubies are almost never clean the way diamonds are, and small silk-like inclusions are normal, even welcome - they prove the stone is natural and can soften the colour beautifully. A ruby that looks too perfect deserves a hard question, not admiration.
Hardness for a lifetime. Corundum is 9 on the Mohs scale, second only to diamond. An antique ruby ring can be worn daily with ordinary care, which is not true of emerald or opal.
Ruby or something else?
| Red stone | How to tell it from ruby |
|---|---|
| Garnet | Warmer, brick-toned red; softer stone; in antique pieces often cut flat or as a cabochon. Very common in Victorian work |
| Spinel | The great historical impostor - several famous "rubies" in crown jewels are spinels. Beautiful in its own right, now collected on its own merits |
| Synthetic ruby | Chemically real corundum, grown in a furnace. Common and legitimate in jewelry after about 1905 - see below |
| Red glass (paste) | Warm to the touch, bubbles under a loupe, scratches easily. Honest in Georgian work, dishonest when sold as ruby |
The synthetic question every vintage buyer should understand
From the early 1900s, flame-fusion synthetic rubies were produced commercially and used openly across European jewelry - especially in the 1910s to 1950s, when war made natural stones scarce. They are chemically genuine corundum, they were not a scam, and a 1940s ring wearing its original synthetic ruby is historically correct exactly as it is.
What matters is knowing which you are buying, because the price difference is enormous. This is a laboratory question, not a guessing game: I test the pieces that pass through here, and describe every stone as what it is. Ask any seller the direct question - natural or synthetic - and expect a direct answer.
A century old and still sitting perfectly: rubies and diamonds sharing an 18K Danish bangle from the 1920s.
Rubies through the eras
Victorian: rubies in snake rings, hearts and half-hoops, often paired with diamonds or pearls, the stone of declared love. Edwardian and Art Deco: calibré-cut rubies lining platinum geometry, and cabochons in the twenties. Mid-century: Scandinavian goldsmiths set rubies - natural and synthetic alike - into clusters, stars and cabochon rows where the red lifts the gold. July's birthstone, the 40th anniversary stone, and at every point in that story: the colour of the heart.
Buying an antique ruby well
Buy the colour first, the size second. A small stone of vivid red beats a large muddy one every time, both on the hand and at resale. Insist on knowing natural versus synthetic, ask whether the stone shows signs of heat treatment if the price implies natural, and remember the setting is evidence: a genuine period setting with a genuine period stone is worth more than either part alone.
Frequently asked questions
What are rubies actually made of?
Corundum, the same mineral as sapphire, coloured red by chromium. Red corundum is called ruby; every other colour is called sapphire.
Are rubies rarer than diamonds?
Fine natural rubies of good size are considerably rarer than equivalent diamonds, which is why top rubies fetch higher per-carat prices than white diamonds.
What is a pigeon blood ruby?
The trade's name for the most prized colour: a pure vivid red with a faint blue undertone, historically associated with Burmese stones.
Are the rubies in vintage jewelry real?
Often, but synthetic rubies were used openly and legitimately from about 1905 onward. They are chemically real corundum. A serious dealer tests the stones and tells you which you are looking at.
Can I wear an antique ruby ring every day?
Yes. At hardness 9, ruby is second only to diamond and handles daily wear well. The setting, not the stone, is what needs an occasional check.
How do I tell ruby from garnet?
Garnet runs warmer and more brick-toned, and is noticeably softer. In antique jewelry, context helps too: Victorian garnets are usually flat-cut or cabochon in closed or foiled settings.
Read next: Garnet vs ruby · Are sapphires only blue? · Birthstones by month
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