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· Al₂O₃ · 9

Ruby

Ruby is red corundum, aluminium oxide coloured by a trace of chromium. It is the second-hardest natural gem after diamond. Mined ruby of fine colour is one of the most expensive gems on earth; lab-grown ruby is the same mineral, grown in a flame in a few hours, and costs cents to a few dollars a carat.

From the ground to your hand

The same stone at four moments. Tap a photo of a listing to see it on Amazon.

  1. 01 In the ground (step 1 of 4)

    Natural ruby crystals in white marble, Luc Yen, Vietnam. Ruby grows where limestone was cooked into marble deep inside mountain belts.

    Natural ruby crystals in white marble, Luc Yen, Vietnam. Ruby grows where limestone was cooked into marble deep inside mountain belts.

    Real specimen. Photo: Robert M. Lavinsky, CC BY-SA 3.0.

  2. 02 Out of the furnace (step 2 of 4)

    A lab ruby boule, one single crystal grown drop by drop in a hydrogen-oxygen flame (600 ct).

    A lab ruby , one single crystal grown drop by drop in a hydrogen-oxygen flame (600 ct).

    Amazon listing photo. See it on Amazon

  3. 03 Cut (step 3 of 4)

    Cut from a boule: a 29.83 ct emerald-cut lab ruby, 20 x 15 mm.

    Cut from a boule: a 29.83 ct emerald-cut lab ruby, 20 x 15 mm.

    Amazon listing photo. See it on Amazon

  4. 04 Set (step 4 of 4)

    Set in jewellery: a created ruby solitaire in sterling silver.

    Set in jewellery: a created ruby solitaire in sterling silver.

    Amazon listing photo. See it on Amazon

Mineral
Corundum (aluminium oxide)
Colour from
Chromium
Hardness
9 on the Mohs scale
Grown in labs since
1902 (flame fusion)
Famous sources
Myanmar, Mozambique
A ruby crystal from Mogok, Myanmar, the most famous ruby source in history.
A ruby crystal from Mogok, Myanmar, the most famous ruby source in history. Photo: Robert M. Lavinsky, CC BY-SA 3.0.
Ruby on marble from Jegdalek, Afghanistan, mined since antiquity.
Ruby on marble from Jegdalek, Afghanistan, mined since antiquity. Photo: Marcin Mlynczak, Public domain.

Famous ruby in museums

What the finest natural stones look like: real pieces in public collections. The whole gem museum.

The Carmen Lúcia Ruby: About 23.1 carats, one of the largest fine faceted rubies from Myanmar on public display.
The Carmen Lúcia RubyAbout 23.1 carats, one of the largest fine faceted rubies from Myanmar on public display.Smithsonian National Museum of Natural HistoryA clean Burmese ruby this size is far rarer than a diamond of the same weight.Photo: thisisbossi, CC BY-SA 2.0.

Own a lab version, or a natural one

Lab-grownLab ruby, oval, 20.5 ct, 20 x 15 mmabout $30on Amazon →NaturalNatural Burmese ruby, 5.11 ct, unheated, GIA reportabout $17,250on Amazon →

The lab oval is nearly the Carmen Lucia size. The biggest fine natural ruby we could find for sale is a Burmese stone like the Carmen Lucia, but under a quarter of its weight, and it costs about 575 times as much as the lab stone.

The Rosser Reeves Star Ruby: About 138.7 carats, a star ruby from Sri Lanka.
The Rosser Reeves Star RubyAbout 138.7 carats, a star ruby from Sri Lanka.Smithsonian National Museum of Natural HistoryIts owner, an advertising executive, carried it as a lucky charm before giving it to the museum.Photo: thisisbossi, CC BY-SA 2.0.

Own a lab version, or a natural one

Lab-grownLab-created star ruby cabochon, ovalabout $15on Amazon →NaturalNatural Burmese star ruby, 17.83 ct, untreated, GRS reportabout $3,600on Amazon →

The same six-rayed star in red, natural or lab-grown.

The DeLong Star Ruby: About 100 carats, a Burmese star ruby with a sharp six-rayed star.
The DeLong Star RubyAbout 100 carats, a Burmese star ruby with a sharp six-rayed star.American Museum of Natural History, New YorkTaken in the same 1964 museum burglary as the Star of India, and bought back for a ransom months later.Photo: Vicpeters, CC BY 4.0.

Own a lab version, or a natural one

Lab-grownLab-created star ruby cabochon, ovalabout $15on Amazon →NaturalNatural Burmese star ruby, 17.83 ct, GRS reportabout $3,600on Amazon →

The same six-rayed star, lab-grown or from Burma.

The Crown of Princess Blanche: A gold crown set with sapphires, rubies, emeralds, diamonds and pearls, made around 1370 to 1380.
The Crown of Princess BlancheA gold crown set with sapphires, rubies, emeralds, diamonds and pearls, made around 1370 to 1380.Treasury of the Munich ResidenceIt is the oldest surviving crown from England. It left with Princess Blanche when she married into a German royal family in 1402.Photo: Allie Caulfield, CC BY 2.0.

Own a lab version

Lab-grownLab sapphire tennis necklace, 9.4 ct total, white goldabout $350on Amazon →

A full line of blue sapphires, lab grown.

A Mughal hookah base of jade, lapis and rubies: A jade huqqa (hookah) base inlaid with lapis lazuli and rubies set in gold, Mughal India, about 1700, later mounted in Paris in 1798.
A Mughal hookah base of jade, lapis and rubiesA jade huqqa (hookah) base inlaid with lapis lazuli and rubies set in gold, Mughal India, about 1700, later mounted in Paris in 1798.British Museum, LondonMughal workshops set gold, lapis and rubies flush into pale jade. A French jeweller later gave it a gilt stand, so it is half India and half Paris.Photo: Daderot, CC0.
St Edward’s Crown: The crown used at the moment of coronation in Britain, made in 1661 of solid gold and set with sapphires, rubies, amethysts, garnets and other gems.
St Edward’s CrownThe crown used at the moment of coronation in Britain, made in 1661 of solid gold and set with sapphires, rubies, amethysts, garnets and other gems.Jewel House, Tower of LondonIt replaced a medieval crown melted down after the English Civil War. It weighs over 2 kg and is worn only for a few minutes, at the crowning itself.Photo: Firebrace, Public domain.
The Crown of Bavaria: The crown of the Kings of Bavaria, made in Paris in 1806 and 1807 by the jeweller Marie-Étienne Nitot with the goldsmiths Leblond and Biennais.
The Crown of BavariaThe crown of the Kings of Bavaria, made in Paris in 1806 and 1807 by the jeweller Marie-Étienne Nitot with the goldsmiths Leblond and Biennais.Treasury of the Residenz, MunichBavaria became a kingdom in 1806 with Napoleon’s backing, so the new king ordered his crown from Napoleon’s own jewellers.Photo: Jebulon, CC0.
A Mughal jade wine cup set with rubies and emeralds: A wine cup of jade inlaid with gold, rubies and emeralds, made in Mughal India in the 18th century.
A Mughal jade wine cup set with rubies and emeraldsA wine cup of jade inlaid with gold, rubies and emeralds, made in Mughal India in the 18th century.Guimet Museum (Musée Guimet), ParisMughal jewellers set gems into jade so finely that the gold lines look painted on.Photo: Vassil, Public domain.
The Crown of Stephen Bocskai: A gold crown set with rubies, spinels, emeralds, turquoises and pearls, given by the Ottoman sultan to Stephen Bocskai, Prince of Transylvania, in 1605.
The Crown of Stephen BocskaiA gold crown set with rubies, spinels, emeralds, turquoises and pearls, given by the Ottoman sultan to Stephen Bocskai, Prince of Transylvania, in 1605.Imperial Treasury (Kaiserliche Schatzkammer), ViennaA Muslim sultan crowned a Protestant prince, and the crown ended up in the treasury of the Catholic Habsburgs he had fought.Photo: Dennis G. Jarvis, CC BY-SA 2.0.
A Mughal mango-shaped flask: A 6.5 cm flask in the shape of a mango, made of two halves of rock crystal held by gold wire scrolls set with rubies and emeralds, with enamel.
A Mughal mango-shaped flaskA 6.5 cm flask in the shape of a mango, made of two halves of rock crystal held by gold wire scrolls set with rubies and emeralds, with enamel.Metropolitan Museum of Art, New York (1993.18)The Met dates it to the reign of Shah Jahan, builder of the Taj Mahal, when the Mughal court loved jewelled objects shaped like nature.Photo: Metropolitan Museum of Art, CC0.
A centaur made from a baroque pearl: A pendant 8.9 cm high whose body is one irregular baroque pearl, finished in enamelled gold set with sapphires and rubies, with more pearls hanging below.
A centaur made from a baroque pearlA pendant 8.9 cm high whose body is one irregular baroque pearl, finished in enamelled gold set with sapphires and rubies, with more pearls hanging below.Metropolitan Museum of Art, New York (1982.60.381)Renaissance goldsmiths let the odd shape of a pearl suggest the creature, here the half-man, half-horse of Greek myth.Photo: Metropolitan Museum of Art, CC0.

Mined vs lab-grown ruby

Mined and lab-grown ruby are the same mineral; this is what differs
MinedLab-grown
How it formedOver millions of years in marble or basaltIn a flame furnace in hours (flame fusion), or in months (flux)
InsideSilk, crystals, straight colour zonesUsually clean; and round bubbles in flame-fusion stones
TreatmentUsually heated; cheap stones may be glass-filledNormally none
PriceHundreds to many thousands of dollars a carat for good colourCents to a few dollars a carat
ResaleFine stones hold valueVery little

Treatments. Most mined ruby is heated to improve colour and clarity, which is permanent and accepted. Watch for glass-filled ruby: heavily cracked stones filled with lead glass and sold as huge, cheap "natural" rubies. All gem treatments explained.

Where natural ruby comes from

Pins mark mining districts, not exact mines. Drag to move, pinch or scroll to zoom, tap a pin to read about it. Map data © OpenStreetMap contributors.

List of every place on the map (4)
  • Ruby: Mogok, Myanmar. The most famous ruby source in history, prized for "pigeon's blood" red.
  • Ruby: Montepuez, Mozambique. Discovered in 2009 and now a leading source of fine ruby.
  • Ruby: Chanthaburi, Thailand. Once a major mining area; now mainly a cutting, heating and trading hub.
  • Ruby: Jegdalek, Afghanistan. Marble-hosted ruby, mined since antiquity.

How it is cut

Lab ruby is mostly machine-cut in calibrated sizes, which is why a cut lab stone costs little more than its rough. Fine mined stones are often native-cut to keep weight, then recut by precision cutters. See cuts from easiest to hardest and whether cutting your own is cheaper than buying cut.

What to buy

Checked in stock on October 10, 2026. Photos are the listings' own; prices are rounded.

All 19 checked ruby picks

See them all The full catalog 195 For women 7For men 1Loose stones 6Beads 6
All checked lab rubiesBig lab gemsAre lab rubies real rubies?Is a cheap natural ruby real?

The ruby shop: 127 more pieces we trust

Every piece names the real stone and comes from a seller with a record, checked in stock on October 11, 2026. Photos are the listings' own; prices are rounded.

Loose stones20.5 ctGryrigns lab ruby, oval, 20 x 15 mmThe oval version of the same size. An oval is shallower than an emerald cut, so it weighs less for the same face.about $30on Amazon →Loose stones33.5 ctGryrigns lab ruby, oval, 25 x 18 mmA stone the size of a large coat button.about $40on Amazon →Loose stones48.3 ctGryrigns lab ruby, oval, 30 x 20 mmThe biggest faceted ruby on the list, and a showpiece for a desk or display case.about $55on Amazon →Loose stones5 ctCHINALUSTER lab ruby, emerald cutSmaller stones for setting in jewellery. We have bought from this seller before and liked the stones.about $20on Amazon →Loose stones5 ctCHINALUSTER lab ruby, pear cut, 9 x 13 mmA teardrop for a pendant or a pair of drop earrings.about $25on Amazon →WomenAmazon Essentials created ruby flower pendant, sterling silverThe cheapest lab ruby necklace we trust: small stones in a flower setting, sold by Amazon itself.about $18on Amazon →WomenAmazon Essentials created ruby three-stone drop earringsLeverbacks close like a latch, so they do not fall out.about $22on Amazon →WomenDECADENCE created ruby heart studs, solid 14K goldReal gold posts at a gift price.about $70on Amazon →Women19.24 ctGem Stone King created ruby pear drop earringsBig pear-shaped drops: lab ruby makes this size affordable.about $50on Amazon →Women5.45 ctEcoGems lab ruby emerald-cut halo necklaceFrom a seller that sells only lab-grown stones.about $110on Amazon →WomenPEORA created ruby heart pendant, 14K white goldPEORA is a lab gem specialist; this is their solid-gold line.about $250on Amazon →MenRaymard bar necklace with a created ruby, sterling silverA plain silver bar with one small ruby: a lab ruby a man can wear every day.about $75on Amazon →

See all 195 in the lab gem catalog

Your kit for ruby

Five tools that let you check what you bought (a loupe, a UV torch, locking tweezers, a gem box and a pocket scale), plus a turntable that spins your stone under the light the way jewellers show one. The full collector's kit.

LookGemOro 10x triplet loupeunder $20LookDARKBEAM filtered 365 nm UV flashlightabout $10HandleHonoson locking tweezers, 3 packabout $10StoreTeensery gem display boxes with clear lids, 10 packabout $9ShowComXim motorized turntable, adjustable speed and directionabout $15MeasureGemOro Platinum XP500 pocket scale, 0.01 gabout $40

In short

Ruby grows over millions of years in the earth, or in hours to months in a lab. Both are real ruby; the mined stone is rare and priced for rarity, the lab stone is priced for the cost of growing it. Buy lab to wear and enjoy, check the listing names the mineral, and test it when it arrives.

See our first pick: Gryrigns 29.83 ct emerald-cut lab ruby, 20 x 15 mm

Frequently Asked Questions

Is a lab ruby a real ruby?

Yes. It is corundum coloured by chromium, exactly what a mined ruby is, with the same hardness and the same optical properties. It must be sold as lab-grown, lab-created, created or synthetic.

What is the difference between ruby and sapphire?

Only colour. Both are corundum; red corundum is called ruby and every other colour, including pink in some markets, is sapphire.

How can I tell a lab ruby from red glass?

Weigh and measure it: corundum is about 60 percent heavier than glass for the same size. Our weight checker does the maths. Lab ruby also glows strong red under a UV flashlight.

Is flux ruby better than flame-fusion ruby?

Not automatically. Cheap flame-fusion (Verneuil) ruby is very clean and even, with curved growth lines and round gas bubbles under magnification, so a big one can look almost too perfect. Flux ruby costs more to grow and traps wispy fingerprints that look more like a mined stone. Ask what a premium changes to your eye before paying it.

Photo credits

  • ruby-in-marble-luc-yen.webp: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons.
  • ruby-crystal-mogok.webp: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons.
  • ruby-on-marble-jegdalek.webp: Marcin Mlynczak, Public domain, via Wikimedia Commons.
  • Product photos: Amazon listings, via the Amazon Product Advertising (Creators) API.

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