The Ceylon Treasury Handbook

Chapter I

Foreword: The Other Ceylon

Anna, our FGAA-qualified gemmologist, on the stones that share the sapphire's gravel — moonstone, cat's-eye and alexandrite — and why the island's second treasury is the best-kept open secret in the coloured world.

The second treasury

There is a small porcelain dish on my assessment bench in Sydney that I use as a party trick. It holds the sorted yield of a single day's washing at a pit in Sabaragamuwa — the kind of parcel the family behind this house has been picking over since the 1960s, three generations of them now. Visitors expect sapphires, and yes, there are sapphires; you can read a whole volume on those in our Sapphire Buyer's Handbook, or browse the Ceylon sapphires themselves. But then I tip the dish under the lamp and let people see the rest: a moonstone with a blue glow that moves when the stone does not, a honey-coloured cabochon with a line of light down its spine that opens and shuts like something alive, a scrap of chrysoberyl that cannot decide what colour it wants to be. That is the moment this handbook exists to explain.

Sri Lanka is filed, in most buyers' heads and in its own export ledgers, under one stone. The Sri Lanka Export Development Board reports that sapphire varieties make up nearly 85 per cent of the island's gem export share — and yet the same board counts roughly 75 varieties of gemstone, from ten mineral species, coming out of those gravels. Everything that is not sapphire travels in sapphire's shadow. For a buyer, that shadow is the most interesting place on the island. It is where the moonstone with the rolling blue sheen lives, and the cat's-eye that once caused a run on jewellers across the British Empire, and alexandrite — the stone that reads green by daylight and red by lamplight and holds a world auction record of US$1.9 million for a single ring.

A word on the name. I use "Ceylon" through this volume the way the gem trade uses it — as the historic trade name that still travels on laboratory reports and auction catalogues — and "Sri Lanka" when I mean the modern country and its modern industry. Both words point at the same gravels. This volume also leans on its siblings: sapphire has its own handbook, spinel its own, certification its own, and where a subject deserves ten pages instead of one paragraph I will send you sideways rather than pretend to cover it here. A library works best when each book trusts the others to do their jobs.

How to read this handbook

Three promises, the same ones I make in every volume of this library. First, mechanisms before mystique: you will learn what adularescence, chatoyancy and colour change actually are, physically, because a buyer who understands the phenomenon cannot be sold the imitation. Second, candour about treatments and impostors: a treated stone honestly disclosed and honestly priced is a legitimate purchase, and I will say so plainly; the sin in this trade is never the treatment, it is the silence. Third, numbers with dates and sources attached. Where I quote a price it will come from a named publication — Rapaport, National Jeweler, GIA's Gems & Gemology, the trade guides — with its year, and where the honest answer is "the market is opaque and the ranges are wide", I will write exactly that rather than invent precision. And none of it, ever, is investment advice. We sell gemstones, not financial products.

One more thing before we go down the shaft. The stones in this book are phenomenal stones in the technical sense — gems whose beauty is an optical event rather than a static colour — and no laboratory on earth issues a grade for the sharpness of an eye or the spread of a sheen. The laboratories will tell you what a stone is; only your own educated eye can tell you whether it is fine. This handbook is my attempt to lend you that eye. Use it slowly, preferably with a cup of tea, ideally near a lamp and a window.

— Anna, FGAA
Ministry of Gems, Sydney

Chapter II

One Gravel, Many Stones: The Geology of the Treasury

A metamorphic terrain more than 550 million years old, rivers that did the sorting, and roughly 75 gem varieties from ten species — why one Ceylon washing pit can yield four different stones before lunch.

Five hundred and fifty million years of preparation

Most gem countries are one-trick geologies. Sri Lanka is not, and the reason is a slab of crust called the Highland Complex — a Precambrian metamorphic terrain, more than 550 million years old by the academic literature, that was cooked and squeezed at granulite grade, which is about as hard as regional metamorphism gets. Under that heat and pressure, alumina-rich rocks recrystallised into a whole family of gem minerals at once: corundum, which gives the island its sapphires and rubies; beryl; spinel; and chrysoberyl, the species that gives us both cat's-eye and alexandrite. One oven, many dishes.

Then the rivers took over. Over millions of years, erosion stripped the highlands and carried the liberated crystals downstream, and because gem minerals are dense, they dropped out of the current together and concentrated in valley floors and buried river channels. Miners call this gem-bearing gravel illam — a word worth knowing, and one you will find alongside the rest of the trade's vocabulary in our Gem Lexicon. The illam is nature's sorting table: a single washing pit can surrender a sapphire, a moonstone, a spinel and a chrysoberyl in the same morning, because the river spent an epoch gathering them into one place. When I say these stones share a gravel, I mean it literally.

Four districts and a missing mother rock

The classic mining geography, as GIA's Gems & Gemology lays it out, runs to four main areas: the Ratnapura district in Sabaragamuwa — the "city of gems", and the heart of the trade — plus Elahera in the Central Province, Okkampitiya in Uva, and Kataragama in the south. Chrysoberyl has its own postcode preference: the notable occurrences concentrate around Morawaka and Deniyaya in the Southern Province. And here is the fact I find most romantic in the whole geology: GIA states that every Sri Lankan alexandrite and chrysoberyl on record has come from alluvial deposits, and that the original source rock has never been found. The island has been mining these stones for centuries and still cannot point to the outcrop they grew in. The rivers know, and the rivers are not telling.

This has a practical consequence that shapes everything in the chapters ahead. Because there is no hard-rock mine to scale up, alexandrite and cat's-eye chrysoberyl are recovered as byproducts of mining for corundum and other gems. Production is, in GIA's words, erratic and unpredictable — so much so that even GIA has found it difficult to secure reliable parcels for its own reference collection. When the world's largest gemmological institute struggles to buy study stones, you begin to understand why fine cat's-eyes and alexandrites surface in ones and twos, and why patience is a genuine buying skill in this corner of the market.

An industry larger than its ledger

Now the numbers, because they frame the opportunity. Declared exports of Sri Lankan gems, diamonds and jewellery came to US$381.9 million in 2024 — down more than 23 per cent from around US$500 million in 2023, per the Export Development Board's figures. Sapphire varieties account for nearly 85 per cent of the gem export share. But the declared figures are only part of the story: in October 2025 the Sunday Times in Colombo reported that irregular, undeclared gem exports exceed US$1 billion — meaning the formal statistics understate the real trade by a wide margin. The island is also, per the EDB, the world's second-largest supplier of spinel, in colours from ruby-red through to the rare and coveted cobalt blue; spinel gets its own full volume in this library, The Spinel Handbook, so I will leave it there with a respectful nod.

What should a buyer take from all this? Three things. Supply of the non-sapphire stones is thin, informal and passes through many hands before it reaches a shop window — which makes paperwork and supplier candour more important here, not less. Second, the very fact that the trade's attention is fixed on sapphire means the other stones are under-studied by sellers too; a buyer who has read one careful handbook is, frankly, ahead of half the counter staff they will meet. And third: when a gravel this generous concentrates four species into one pit, a thoughtful collection can hold a moonstone, a cat's-eye and a spinel that are all, in the deepest sense, from the same river.

Chapter III

Moonstone: The Glow from Meetiyagoda

Adularescence is light doing something no other gem does — how the blue sheen works, how it is judged, and what the hand-dug shafts of Meetiyagoda actually send up the winch.

What the glow actually is

Moonstone is the only gem I know that looks better the less it tries. It is a variety of orthoclase feldspar — chemically humble, common as sand — but during cooling, two feldspars, orthoclase and albite, separate into stacked, alternating layers finer than a wavelength of light. Light entering the stone scatters between those thin layers, and the result is adularescence: a soft billow of glow that appears to roll across the surface as you move the stone, the way moonlight rolls on water. That description of the mechanism is GIA's, and I cannot improve on the physics, only on the poetry: the glow is not in the stone the way colour is in a sapphire. It is an event that happens between the stone and your eye, freshly, every time you tilt your wrist.

Under the microscope, moonstone signs its own name. The characteristic inclusions are tiny tension cracks that gemmologists call "centipedes" — little many-legged fractures that look exactly as advertised. Finding them is one of the quiet pleasures of the bench, and one of the quick reassurances that a stone is the real feldspar rather than borrowed glass.

Judging the sheen

GIA's stated ideal for fine moonstone is precise, and worth memorising before you shop: a colourless, semitransparent-to-nearly-transparent body, free of yellowish, brownish or greenish tints, carrying a vivid blue adularescence — the trade says "blue sheen" — centred on top of the cabochon and visible across a wide range of viewing angles. That last clause is the professional's test. A stone whose sheen only ignites in one narrow position drops sharply in value; a fine stone keeps its glow alive as it swings through a wide arc. When I assess one in the Sydney workroom I rock it slowly under soft daylight from a south-facing window and simply count the degrees of travel before the light dies.

Cut matters more than most buyers realise. Adularescence needs a dome: GIA is blunt that very flat cabochons display the sheen poorly and have little value, so dome height is not a styling preference, it is an optical requirement. Size has a practical ceiling too — the International Gem Society notes that fine blue-sheen moonstone rarely exceeds 15 to 20 carats, and that the finest historic source, Myanmar, is essentially depleted, leaving Sri Lanka as the premier origin for blue-sheen stones today. There are side varieties worth knowing: some moonstones show a cat's-eye, a few show four-rayed stars, a "parrot green" type turned up in southern India in 1997, and peach is a popular commercial colour. Lovely things, all — but the blue sheen on a colourless body is the queen, and Ceylon is her home address. One lab-bench footnote for the sceptics: Sri Lankan moonstone tends to a slightly lower specific gravity, around 2.56 against roughly 2.59 for Indian material — the sort of small, dull, wonderful number that lets a gemmologist separate parcels when the labels have gone missing.

Let me give you the counter routine I actually use, in order, so the criteria stop being a list and become a sequence. First, body: hold the stone against a white card and hunt for yellow, brown or green tints — the finest stones read colourless to icy. Second, transparency: the sheen should float over depth, not sit on milk. Third, the arc: rock the stone through a wide swing under soft daylight and watch where the glow lives and dies; a fine stone keeps it burning through a generous arc, a poor one flashes once and goes dark. Fourth, the dome: profile the cabochon side-on — height is not vanity, it is optics. Fifth, the loupe: look for the centipedes, welcome them, and check the back for the tell-tale iridescent film of a coating while you are there. Ten minutes, no instrument grander than a loupe, and you will have out-examined most of the buyers that stone will ever meet. Sri Lankan against Indian material, side by side, usually resolves itself at step one and step three.

Meetiyagoda, by hand

The name to know is Meetiyagoda, a village near Ambalangoda in the island's south-west. The Export Development Board itself names the Meetiyagoda mines as the source of the world's celebrated blue moonstones, and the mining there remains almost defiantly pre-industrial. Kim Rix, a GIA graduate gemmologist who documented the workings in the field, describes shafts dug by hand through the topsoil, propped with coconut-wood scaffolding lined with fern leaves, the gravel hauled up in buckets on a hand-winch. Local accounts speak of shafts around twelve metres deep with branching horizontal tunnels — take that as travel-book colour rather than survey data, but the essential picture is verified: the world's best blue moonstone comes out of the ground in buckets, by muscle, exactly as it did a century ago.

Prices, with the usual candour: there is no auction market for moonstone, so all figures are dealer-derived. The International Gem Society's data and current dealer pages put collector-grade Sri Lankan blue moonstone at roughly US$50 to US$500-plus per carat, with fine stones above five carats regularly making US$200 to US$500 per carat, while commercial Indian material trades at single-digit dollars per carat. That thousand-fold spread between commercial and collector goods is the entire lesson of this chapter in one number: with moonstone you are paying for the quality of an optical event — body transparency, blueness of sheen, breadth of angle, height of dome — and almost nothing else. Train your eye on those four things and you can shop for moonstone anywhere in the world without a chaperone.

Chapter IV

Borrowed Names: The Moonstone Impostors

Rainbow moonstone is not moonstone and opalite is not a gemstone at all — a short field guide to borrowed names, quiet coatings and the questions that get you the truth.

The labradorite with a stage name

Let us deal with the elephant in the display case. "Rainbow moonstone" — that milky material flashing electric blue and violet, sold on every high street and in every crystal shop — is not moonstone. It is transparent labradorite, a plagioclase feldspar, which is a different mineral from the orthoclase family that true moonstone belongs to, working by a different optical mechanism: light interfering at lamellar twinning planes, rather than scattering between orthoclase and albite layers. This is not my private pedantry; it is GIA's published position. GIA's own FAQ concedes the material is technically not moonstone, and its Gem Trade Laboratory words the report conclusion "Labradorite—known in the trade as rainbow moonstone" — an explicit, slightly weary accommodation of a trade misnomer. SSEF's Dr Henry Hänni was less diplomatic, telling JCK the name has no justification beyond the commercial, and calling it confusing and incorrect. The material itself has a respectable history — the blue-rainbow labradorite was discovered in southern India around 1986, and GIA documented a fine new Madagascar source in its Spring 2024 Gems & Gemology — and I want to be fair: it can be genuinely beautiful. Buy it happily. Just buy it as labradorite, at labradorite prices, and smile politely at the stage name.

Why do borrowed names persist? Because they work, commercially. "Rainbow moonstone" outsells "transparent labradorite" for the same reason poetry has always outsold mineralogy, and the trade has voted with its labels for nearly forty years, ever since the Indian material surfaced in the mid-1980s. The regulators, for what it is worth, side with the pedants: the FTC's Jewelry Guides in the United States and the ACCC's guidance here in Australia run on the same principle — a name or description that misleads a buyer about what a thing is will eventually cost the seller more than the poetry earned — and Chapter VIII walks through both regimes properly. My own rule is simpler and older than either: the romantic name goes on the gift card, the mineral name goes on the invoice.

Glass in a moon costume

One rung further down lives "opalite", and here there is no mineral at all. Opalite is man-made opalescent glass — occasionally plastic or resin — and it is routinely sold under names like "moonstone", "opal moonstone", "sea opal" and, my personal favourite for sheer audacity, "dragon's breath". The material glows a soft milky blue against dark backgrounds and orange against light ones, which is exactly what engineered glass does and exactly what neither moonstone nor opal does. It is glass, full stop, and should be sold as such. The tell is usually perfection: opalite is flawlessly, monotonously even, with none of moonstone's directional sheen — the glow does not roll or travel as the piece turns — and none of the centipede inclusions from the last chapter. If a "moonstone" necklace costs less than your lunch and glows the same from every angle, you now know what you are holding.

The quiet treatments

What about true moonstone that has been helped along? Here the news is mostly good. Moonstone is typically an untreated gem — one of the reasons I love recommending it — but documented enhancements do exist, and you should know the list: thin vaporised metal-oxide coatings applied to the back of a cabochon to boost the apparent adularescence, which are non-permanent and simply wear away; wax impregnation of surface-reaching fissures; and polymer-filled moonstone, which GIA researchers documented in a Spring 2013 Gems & Gemology study. None of these is common, all of them belong on a receipt, and every treatment we have ever encountered on our own stock is logged openly in our Treatment Register — because, to repeat the house creed, a disclosed treatment honestly priced is legitimate, and an undisclosed one is the only real villain in this book.

The practical protocol, then, whether you are buying from us, from a Colombo dealer, or from a website at midnight (for that last case, do read The Online Gem Buyer's Handbook first): ask, in writing, three questions. Is this orthoclase moonstone, labradorite, or something else? Is it natural and untreated — and if treated, how? And will you put that on the invoice? A seller who answers all three in plain sentences is a seller you can work with. A seller who reaches for the word "mystical" instead of the word "feldspar" is telling you something too.

Chapter V

Cat's-Eye: Milk, Honey and the Unqualified Name

Chrysoberyl alone earns the unqualified name cat's eye — every other species must queue behind it — and the difference is worth up to two orders of magnitude per carat.

How an eye is made

Chatoyancy — the cat's-eye effect — is what happens when a stone is packed with dense fields of minute parallel inclusions, needles and hollow tubes finer than hair, and is cut as a cabochon with its base parallel to those fibres. Light reflects off the fibre field and gathers into a single bright band oriented perpendicular to the needles, and the band glides across the dome as the stone or the light moves. Many species can manage a smeary version of this trick. Chrysoberyl does it better than anything else in nature: the gemmological literature — Gem-A and the standard references — credits chrysoberyl with the sharpest, most precisely defined cat's-eye of any gem species, and the trade agrees with its wallet. Hence the naming convention that this entire chapter turns on: by long trade custom, the unqualified term "cat's eye" means cat's-eye chrysoberyl and nothing else. Every other chatoyant stone must carry its species as a qualifier — quartz cat's-eye, tourmaline cat's-eye, apatite cat's-eye. The naked name is a title, and chrysoberyl holds it.

The mineral itself deserves its rank. Chrysoberyl is beryllium aluminium oxide, BeAl₂O₄, at 8.5 on the Mohs scale with only indistinct cleavage — the International Gem Society calls it one of the toughest stones for jewellery purposes, third among natural gems behind diamond and corundum. The Ceylon ideal, in the Export Development Board's description, is a semi-transparent golden-yellow to greenish- or brownish-yellow body with a sharp chatoyant band that appears to open and shut as the stone moves — an eye that blinks at you. Once you have watched a fine one do this under a single lamp, every lesser eye looks like a smudge.

Milk and honey

The connoisseur's test has the best name in gemmology. Take a fine honey-coloured cat's-eye, light it with a single concentrated source, and view it with your eye at right angles to the light: the stone divides into two halves — milky white on the side facing the light, rich honey on the far side — and as you rotate the stone, the halves swap places. This is the "milk and honey" effect, described in the Antique Jewelry University literature as characteristic of the finest stones. It is not a gimmick; it is a by-product of exactly the dense, uniform fibre field that makes a great eye, which is why it functions as a quality certificate written in light. Beyond milk and honey, the judging criteria are mercifully concrete: the band should be sharp-edged and unbroken, not blurry; bright, with strong contrast against the body colour; dead straight; and centred on the dome. The eye itself should be silvery-white to slightly bluish-white. A crooked, off-centre or milky-edged eye is a discount, whatever the label says.

One market note that will save some readers an afternoon of confusion: search "cat's eye" online and much of what you find is not gemmology at all but Vedic astrology, where the stone is prescribed as lehsunia against the influence of Ketu, and where listings are organised by planetary suitability rather than by eye sharpness. I make no comment on anyone's cosmology — the astrological market is old, sincere and enormous — but be aware that its grading language and ours pass each other without touching. An astrological listing may praise a stone's weight and its planetary fit and never once tell you whether the eye is sharp, centred and bright, or whether the species is chrysoberyl or quartz. If you are buying for the phenomenon, insist on the gemmological facts whatever tradition the seller works in; the five questions at the end of this book work in every language and under every zodiac.

A royal engagement and a supply problem

Cat's-eye has form as an engagement stone — quite literally imperial form. In 1879 the Duke of Connaught, Queen Victoria's third son, gave Princess Louise Margaret of Prussia a cat's-eye engagement ring, and demand surged across Europe and the Empire; Ceylon, then the source of most of the finest cat's-eyes, could not keep up. That Victorian supply squeeze has never really ended, because — as Chapter II explained — the stone is a byproduct of other mining, surfacing when it pleases. The giants are correspondingly famous: the largest known cut cat's-eye is the "Eye of the Lion", a 465-carat oval cabochon, and the largest faceted chrysoberyl is a flawless 245-carat stone from Sri Lanka, both per the International Gem Society's records.

What the eye costs

Now the money, and a confession on behalf of the entire trade: cat's-eye pricing is opaque. There is no public auction depth — the significant sales are private treaty — and the serious wholesale price sheets sit behind paywalls, so what follows are indicative dealer-derived ranges current to 2026, not points. The trade guides put commercial yellowish-green cabochons at roughly US$150 to 1,000 per carat, brownish stones at US$60 to 900, saturated honey material up to around US$2,000, and top sharp-eyed milk-and-honey stones anywhere from US$2,000 to US$24,000-plus per carat in larger sizes — that top band the least certain of all. To our knowledge, no published consumer guide currently anchors cat's-eye prices to dated, quality-described examples, which is why I give you ranges and the grading tools rather than false precision — and, as ever, none of this is investment advice. The number that matters most is the comparative one: quartz cat's-eye trades at roughly US$25 to 200 per carat — one to two orders of magnitude below chrysoberyl — and that gulf is the single most exploited gap in "cat's eye" retail. A tourist bracelet of quartz eyes priced as "cat's eye" is technically wearing a defensible name and practically wearing a costume. Treatments, for completeness: plain chrysoberyl is usually completely untreated, and treatments on cat's-eye are rare but documented — dye, oiling, and irradiation to push dull buff stones toward premium honey. One dealer-education claim holds that such irradiation escapes standard laboratory detection; I have found no major-lab publication confirming that, so I will not assert it — the practical safeguard is the same either way: buy certified, buy from sellers who disclose, and let the price of colour be something you understand rather than something you hope.

Chapter VI

Alexandrite: The Emerald by Day

The rarest thing the gravels surrender: a stone that changes colour with the light it is read by, carrying a Russian name, a Brazilian auction record and a Ceylon size advantage.

A stone named for a czar

Alexandrite was found where no one was looking for it — in Russia's Ural Mountains in the early 1830s, during emerald prospecting on the Tokovaya River. In 1834 the mineralogist Nils Adolf Erik Nordenskiöld named it for the future Czar Alexander II, and the stone became an imperial emblem. The Urals' reign did not last. Twentieth-century mining shifted to beryllium extraction, production waned, and it effectively lapsed with the fall of the Soviet Union in 1991; new Russian production today is typically under two carats per stone, per Rapaport, so fine Russian alexandrite now lives mostly in the estate market, trading on history as much as optics.

What actually changes

The mechanism first, because sellers routinely explain it wrongly. Alexandrite is the colour-change variety of chrysoberyl — same tough 8.5-hardness mineral as the cat's-eye, different party trick. The change is caused by trace chromium, Cr³⁺, substituting for aluminium in the crystal structure, which gives the mineral an unusual light-absorption profile balanced on a knife-edge between transmitting green and transmitting red. Daylight, rich in blue and green wavelengths, tips it green; incandescent lamplight, rich in red, tips it red. It is not pleochroism — alexandrite is also strongly pleochroic, showing green, orange and purple-red down different crystal directions, but that is a separate phenomenon, as GIA's literature is at pains to point out. GIA's fine-quality standard is specific: green to bluish green in daylight, red to purplish red in incandescent light, with moderately strong to strong saturation — too light and the colours lack intensity, too dark and they go blackish. Most fashioned alexandrites weigh under one carat, and prices climb dramatically with size and quality.

Where is the boundary between "alexandrite" and mere greenish chrysoberyl? SSEF in Basel has published the clearest answer, and it has three parts: a moderate to distinct colour change under standard daylight and incandescent conditions; a distinct chromium content; and a distinct chromium absorption band at about 575 nanometres. Stones that shift slightly for iron-related reasons do not qualify — SSEF documented one greenish-brown pretender carrying just 0.002 weight-per-cent chromium against roughly 1.2 per cent iron, six hundred times more iron than chromium, that had been mislabelled alexandrite. SSEF will demote such a stone to plain "chrysoberyl" on the identification line of the report, and I bless them for it.

Ceylon's claim

Sri Lanka entered the alexandrite story in 1923, when fine material was reported from the Pelmadulla deposits in the Ratnapura district, and supply ran steadily until the end of the 1980s, when production dropped. The Ceylon signature is scale: Sri Lankan alexandrites run generally larger than their Russian counterparts and often achieve high clarity — GIA has examined Sri Lankan stones up to 600 carats, and a 65.70-carat faceted Sri Lankan alexandrite, among the largest ever cut, resides in a national museum collection (secondary sources disagree about which museum, so I will leave it at that). The candour clause: the Ceylon average shifts toward yellowish greens and brownish reds — the olive problem — and dealers price change-strength above passports, which is why average Ceylon goods trade below average Brazilian. But GIA's own research paper concedes that finer-quality Sri Lankan material shows colour change from saturated green to red. The Ceylon average is olive; the Ceylon exceptional is world-class. Buy the stone, not the flag. Brazil, meanwhile, supplied the modern legend: the Hematita deposit in Minas Gerais, discovered in 1987 after workings began in late 1986, yielded about 50 kilograms of fine alexandrite in under three months and drew some 3,000 wildcat miners — garimpeiros — to the site, per the Gems & Gemology account. Hematita stones run larger and cleaner than earlier Brazilian finds, with faceted gems to 30 carats showing extraordinary change; the 17.08-carat Whitney Alexandrite at the Smithsonian, gifted in 2009, is a Hematita stone, raspberry to teal. And GIA notes drily that stones from Russia or Brazil can easily command more than Tanzanian or Zimbabwean goods with identical attributes — origin, in this market, is priced like a title of nobility. One calendar note: alexandrite shares June birthstone status with cultured pearl and moonstone, which means two of this handbook's stones — plus the pearl — own a single birth month between them. June readers, you have choices; our Birthstone Handbook adjudicates.

Step back and the origin market resolves into a three-way tug with no winner, only prices. Russia carries the mystique — the czar's name, the depleted mines, the estate premiums Rapaport tracks from US$35,000 per carat upward — but its new stones are small and scarce. Brazil holds the quality benchmarks and the auction records, Hematita having reset expectations for how dramatic a colour change can be. Ceylon holds the size and clarity records, and supplies the patient buyer's bargains: honest, large, olive-leaning stones at a fraction of Brazilian money, with the occasional world-class exception surfacing to embarrass the averages. GIA observes that origin is often used as a factor in establishing value; SSEF insists any origin call is an expert opinion rather than a certainty. Put those two sentences together and you have the truest thing anyone can tell you about this market: the trade prices a probability statement. My advice follows: pay confidently for change-strength you can see with your own eyes, and pay cautiously for a paragraph of geography, however beautifully laminated.

The double phenomenon

Rarest of all is the stone that does both of chrysoberyl's tricks at once. When the dense parallel inclusions of a cat's-eye occur inside an alexandrite, the result is cat's-eye alexandrite: a band of light gliding over a body that is itself changing colour with the light source. GIA calls cat's-eye alexandrite with beautiful chatoyancy plus colour change extremely rare, and its Winter 2019 Gems & Gemology photographed a matched pair of Brazilian stones — 2.43 carats total, from Omi Privé — proving the double phenomenon is not exclusively a Ceylon speciality. Pricing is thin and honest data thinner: Indian retail benchmarks run from about US$185 to US$3,075 per carat, and those figures are best read as a floor, not a ceiling — fine double-phenomenon stones price far higher, case by case, in private. If you are ever offered one with paperwork from a major laboratory at a price that seems reasonable, do telephone me before someone else does.

Chapter VII

The Impostor Problem: A Century of Substitution

The commonest substitution in the coloured-stone trade is a thirty-dollar synthetic sapphire wearing alexandrite's name — the hundred-year history, the instant test, and the honest lab-grown alternative.

The vanadium trick

If I could hang one warning sign over the entire alexandrite market, it would read: the impostor is not what you think it is. The stone most often sold as alexandrite is not lab-grown alexandrite at all — it is synthetic colour-change corundum, a sapphire doped with vanadium, mass-produced since the early 1900s and sold by the tonne, for decades, under alexandrite's name. It saturates mid-century jewellery; it fills a hundred years of tourist purchases and souvenir rings; it is, in my experience and in the trade literature alike, by far the most common alexandrite impostor there is. I meet it on the Sydney bench several times a year, usually inside an inherited ring, usually attached to a story about a grandfather and a port city, and there is no sadder routine in this job than dismantling a family legend over a loupe. The tell, before any instrument comes out: the synthetic shifts from a greyish or steely blue to a dull purple — blue-to-purple, not green-to-red. Real alexandrite reads green to bluish green in daylight and red to purplish red under a warm globe. If a "colour-change" stone offers you mauve, be suspicious. The economics explain the century of persistence: a two-carat synthetic colour-change sapphire retails around US$30, while a two-carat fine natural alexandrite can sell for about US$30,000 — the Mardon Jewelers trade blog's illustrative figures, and a thousand-to-one incentive to borrow a name.

Sixty seconds with a refractometer

Here is the beautiful part: this hundred-year-old fraud dies in under a minute in any gemmological workroom. Corundum and chrysoberyl are different minerals with different refractive indices — corundum reads 1.759 to 1.778 on a refractometer, chrysoberyl 1.741 to 1.760 — and the instrument does not care about anyone's grandfather. You, at home, can run the softer version: view the stone in indirect daylight from a south-facing window, note the colour honestly, then move it under a warm incandescent lamp and note again. Green-family to red-family is the alexandrite signature; blue-family to purple-family is the synthetic sapphire signature. Neither your eye nor mine substitutes for paperwork on a stone of consequence — an identification report from a major laboratory costs a sliver of any genuine alexandrite's price and settles species, natural-versus-synthetic and treatment in one document. On a four-figure stone, skipping the report to save a hundred dollars is not thrift; it is a bet at terrible odds.

A gentler word for those who have just recognised grandmother's ring in this chapter. Do not tear the stone out, and do not grieve prematurely: have it identified properly first, because a pleasing number of mid-century "alexandrites" turn out to be the real thing, and even where the stone is synthetic sapphire, the ring around it is often fine gold work with worth of its own. A synthetic identified is not a treasure destroyed — it is a family object that has stopped lying to you, which I count as an upgrade. The sadness, where there is any, belongs to whoever pocketed the difference decades ago, not to the hands the ring has passed through since. Bring the ring in, learn what it is, and then decide what story you want it to tell the next generation.

The honest synthetic

True lab-grown alexandrite does exist, and it deserves a fair hearing rather than a scare story. Chatham first synthesised flux-grown alexandrite in 1972, and laboratory-grown stones retail from roughly US$400 — real chrysoberyl, real chromium, real colour change, grown in months instead of geological ages. Under the US FTC's Jewelry Guides it must be clearly and conspicuously described as laboratory-grown, right next to the word alexandrite, every time. Our position is the same as it is for every lab-grown stone, set out at length in The Natural vs Lab-Grown Handbook: a magnificent product when labelled truthfully, a fraud when not, and never, ever the same thing as a natural stone at resale. The label is the whole game.

The number that is not on the report

One more impostor, subtler than the rest: a percentage. Online listings love to advertise "90 per cent colour change" or "95–100 per cent — investment grade". Search any major laboratory's documentation for that scale and you will not find it. GIA describes colour change qualitatively — weak, moderate, strong — by how much of the stone shifts and how saturated the two colours are; SSEF, as we saw, demands a moderate-to-distinct change plus the chromium evidence before the word alexandrite appears at all. No major lab publishes a percentage system. To our knowledge, this is the first consumer handbook to say that plainly: percentage colour change is seller language, not laboratory language, and "investment grade" attached to it is marketing squared — which is reason enough to repeat that nothing in this book is investment advice. When a listing leads with a percentage, ask a simpler question: what does the laboratory report say, and who wrote it?

Chapter VIII

Paper, Prices and the Rules

What a laboratory report can and cannot say about a phenomenal stone, what the auction record books actually show, and what Australian and American law require a seller to tell you.

What a report can and cannot say

Paperwork for the Ceylon treasury comes in two distinct strengths, and knowing which one a stone deserves will save you both money and disappointment. For moonstone and cat's-eye chrysoberyl, laboratories issue identification reports: species and variety, natural versus synthetic or imitation, and treatment detection. That is all, and it is enough — there is no laboratory grade for sheen breadth or eye sharpness, so the quality judgement stays with you and your dealer, which is precisely why Chapters III and V trained your eye. For alexandrite, a second tier exists: the origin opinion. GIA began alexandrite origin research in 2016 and launched the service in early 2019; its reference data supports origin calls for Russia, Brazil, Sri Lanka, Tanzania and India, built from trace-element chemistry, colour-change ranges and inclusion scenes. SSEF — issuing alexandrite reports alongside its corundum work — is careful to describe any origin call as an expert opinion, formed by comparing the stone against a reference collection, not a certainty; and remember its power to demote a weak-change stone to plain chrysoberyl. Gübelin has issued coloured-stone reports since 1923 and sits with GIA and SSEF as the practical top tier for a serious alexandrite, with AGL, GRS and Lotus also active in coloured stones. The full machinery of reports — what each laboratory will and will not commit to paper — has its own volume in this library, The Certification Handbook. Here I will only add the house corollary: every stone we sell carries its laboratory paperwork plus our own Digital Gemstone Passport, so the disclosure survives the receipt.

Which paper should you actually pay for? A rule of thumb from our own bench. For moonstone and cat's-eye at everyday prices, a competent identification — species, natural, treatment status — is proportionate, and on modest pieces a written invoice description from a disclosed, reputable seller may reasonably stand in for a laboratory visit. The moment a cat's-eye crosses into serious four-figure territory, identification from a major laboratory stops being optional. For alexandrite the ladder has a third rung: on fine stones, where the Russia-versus-Brazil-versus-Ceylon question can move the price by multiples, an origin opinion from GIA, Gübelin or SSEF earns its fee many times over — and on cheap stones it would be the most expensive thing about the purchase. Match the paper to the price, and remember that no report anywhere grades the beauty of a phenomenon; that judgement remains gloriously, stubbornly human.

The record books

Now the numbers that make the newspapers, dated and sourced. The world auction record for alexandrite was set at Sotheby's New York on 11 December 2024: a 16.53-carat oval alexandrite ring sold for US$1.9 million — roughly US$114,913 per carat, more than three times its US$600,000 high estimate — a stone the trade press, National Jeweler among them, identifies as Brazilian, untreated and highly transparent. The same sale moved a pair of alexandrite earrings, 7.69 and 7.38 carats, at US$1.2 million, and a 40.52-carat unmounted stone at US$216,000 — three lots totalling US$3.3 million in one December evening. Earlier markers, as compiled in dealer round-ups of the auction results: a 21-carat Russian alexandrite at about US$60,000 per carat at Christie's Geneva in 2014, and Brazilian material at roughly US$90,000 per carat at Phillips in October 2024. Beneath the fireworks, Rapaport's dealer benchmarks sketch the working market: Russian estate stones from about US$35,000 per carat, exceeding US$100,000 above three carats; Brazilian goods at US$10,000–20,000 per carat for one-to-two-carat stones, US$15,000–35,000 for two-to-three, and US$35,000–50,000 up to five carats; Sri Lankan, Indian and African material cheaper, generally weaker in change, but available in sizes above five carats where the others simply stop existing. Read the pattern and you see the whole market's value system in one line: buyers pay for change-strength first, origin second, size third. And the plain line I promised in the foreword, stated where the biggest numbers live: none of this is investment advice. Auction records describe two bidders on one evening, not your stone's future; if you want the broader market weather, our free Gem Market Report is updated annually, and a stone's first job remains being worn and loved.

What the law says a seller must tell you

Finally, the rules — because buyers are better protected than most of them know. In the United States, the FTC's Jewelry Guides (16 CFR Part 23, first issued in 1957, last revised in 2018) make it deceptive to use a gem name — "alexandrite", "moonstone", "cat's eye" — for a laboratory-grown, synthetic, imitation or simulated stone without clear, conspicuous qualification immediately alongside the name, and they require treatment disclosure wherever a treatment affects value, durability or care. Here at home, the Australian Consumer Law does comparable work: describing a treated stone as natural without disclosure can be misleading conduct, and the ACCC's jewellery-industry guidance — first published in 2005 — says that where a treatment is difficult to detect it is prudent to disclose it, that lab-grown stones must be disclosed as such, and that a retailer who supplies a misleading valuation contravenes the Act regardless of whether they knew it was misleading. For purchases covered by the Australian Consumer Law as consumer purchases, the statutory guarantees — that goods are of acceptable quality and match their description — sit underneath every invoice, wherever the seller may prefer you not to look. Which returns us, as everything in this library does, to the one-sentence protocol: get the species, the treatment status and the origin claim in writing, on the invoice, every time. Honest sellers do not flinch at that request. The other kind flinch beautifully.

Chapter IX

Living with the Treasury

One gravel, three very different constitutions — how to set, wear, clean and store each of these stones according to what it can genuinely survive.

Three constitutions

Here is the paradox to hold onto: stones the same river gathered after half a billion years in the rock demand completely different lives above ground. The chrysoberyl family — cat's-eye and alexandrite alike — is built for anything: 8.5 on the Mohs scale, excellent toughness, no cleavage of practical concern, which per GIA makes it one of the best coloured stones in existence for a daily-wear ring, and ultrasonic and steam cleaning are usually safe unless a stone is fracture-filled. Spinel, at 8, is ring-safe too. Moonstone is another animal entirely: 6 to 6.5 on the scale with poor toughness and two directions of cleavage, meaning a single hard knock on a bench corner can split it; GIA notes bluntly that manufacturers usually set moonstone into pendants, earrings and pins rather than rings. It dislikes sudden temperature change, it is attacked by hydrofluoric acid, and its cleaning instructions are the gentlest in gemmology: warm soapy water only — ultrasonic and steam cleaners are never recommended. And one fact I wish every owner knew: ordinary household dust contains quartz, which at Mohs 7 is harder than moonstone, so even routine wiping slowly abrades an unprotected stone over the years. Dust, given decades, is sandpaper.

Settings that tell the truth

Good setting design is durability advice made permanent. For moonstone: bezels and halos that shield the girdle, pendant and earring commissions before ring commissions, removal before gardening, gym and renovation, and separate storage in a soft pouch — because in a shared jewellery box it will lose every argument with its old gravel-mates, sapphire included. If your heart is set on a moonstone engagement ring, it can be done with protective design and honest expectations, but I will always tell you what GIA's care page tells me — and our Care & Heirloom Handbook covers the long game of insurance, heirloom planning and repairs in detail. For the chrysoberyls, the brief inverts: wear them everywhere, and give the lapidary decisions the attention instead. A cat's-eye needs a properly domed cabochon with the fibres parallel to the base or the eye dies in the cutting; an alexandrite deserves settings that let light reach it from all sides, since its whole personality is a conversation with illumination. All of this is exactly the sort of brief our workshop takes daily for commissioned pieces.

The counter checklist

Let me fold the whole handbook into the five written questions I would ask at any counter, anywhere on earth. One: exactly what species is this — is the "cat's eye" chrysoberyl, is the "moonstone" orthoclase feldspar, is the "rainbow moonstone" sold as labradorite? Two: is it natural, laboratory-grown, or an imitation — and will you write that word on the invoice? Three: is it treated, and how — coating, wax, polymer, dye, oil, irradiation — and is the treatment priced accordingly? Four: what does the laboratory report say, which laboratory wrote it, and may I see it before paying? Five, for alexandrite only: describe the colour change to me in plain words — which green, which red, under which lights — and let me see it under daylight and a warm lamp myself before we speak of percentages. A seller who passes all five is a keeper, whatever their address. And that porcelain dish on my bench in Sydney is always worth a visit: the moonstone still rolls its light, the cat's-eye still blinks, the little chrysoberyl still cannot make up its mind — and now you know exactly what each of them is worth, and why. Come and argue with me about it; it is my favourite part of the job.