39 Fun Facts About Diamonds

While a decoy sailed under guard by steamer, how did the 3,106-carat Cullinan rough reach London in 1905?

By registered post, in a plain box: the parcel locked in the steamer captain's safe and watched by detectives for the whole voyage held a fake, there only to draw off thieves.

Harry Winston sent the Hope Diamond to the Smithsonian in 1958 wrapped in plain brown paper; how much was the postage?

$2.44 was the postage; the rest of the $145.29 bill was insurance for $1,000,000, and the brown-paper package itself is now kept in the Smithsonian's collection.

Which French queen's name was wrecked by the 1785 Affair of the Diamond Necklace, a con she never took part in?

Marie Antoinette had turned the necklace down; the adventuress Jeanne de Valois-Saint-Rémy forged her signature to get it from the Crown jewellers, and the queen's gossip-battered reputation never recovered.

Which 1985 Madonna video restages Marilyn Monroe's pink-gown number from Gentlemen Prefer Blondes, suitors and all?

Material Girl restages 'Diamonds Are a Girl's Best Friend' but undercuts the lyric: in the video's story the star shrugs off rich admirers and falls for a director who poses as penniless.

Blood Diamond (2006), with DiCaprio as a Rhodesian smuggler, is set in which country's 1999 civil war?

Sierra Leone's rebels really did pay for their war with gems dug by forced labour, and the outcry led in 2003 to a global scheme certifying rough diamonds as conflict-free.

Which US state's Crater of Diamonds park lets visitors keep any gem they find, on the field that yielded the Uncle Sam?

Arkansas farmer John Huddleston found the first two diamonds there in 1906; mining companies kept failing on the site, and the state bought it in 1972 as a dig-it-yourself park.

On Friedrich Mohs's scratch-hardness scale, diamond takes the top value, which is what number?

10 is only a rank, not a measure: the step from corundum at 9 to diamond is by far the biggest on the scale, about a fourfold jump in absolute hardness.

The carat used to weigh diamonds is named after the seed of which tree, long used by gem traders as a weight?

Carob seeds were trusted because their mass was believed to vary little, and the word reached English via Italian carato, Arabic qīrāṭ and Greek kerátion.

Who founded De Beers Consolidated Mines in 1888, bankrolled by Alfred Beit and the Rothschild bank?

Cecil Rhodes won a furious share-buying battle against his great rival Barney Barnato, who then agreed to fold his own mines into the new company.

Which fictional spy's 1956 adventure took its title from the De Beers advertising slogan 'A Diamond Is Forever'?

James Bond's fourth novel got its name after Ian Fleming spotted the line in an American magazine advert; copywriter Frances Gerety had written it for De Beers in 1947.

Where did a De Beers campaign launched in 1967 lift diamond engagement rings from under 5% of brides to 60% by 1981?

Japan had not even allowed diamond imports until 1959; by the 1980s De Beers adverts there asked for three months' salary, against two in America.

Grace Kelly wore her real Cartier engagement ring from Prince Rainier on screen in which 1956 film, her last?

High Society needed an engagement ring for its heroine, so Kelly simply wore her own; Rainier is said to have proposed with a ruby-and-diamond band before buying the big Cartier stone.

Who bought Elizabeth Taylor a 69-carat pear-shaped diamond in 1969, a day after Cartier outbid him for it at auction?

Richard Burton paid Cartier $1.1m for the stone it had won for $1,050,000, then a record for a publicly sold jewel, and crowds queued in New York and Chicago to see it.

Who first sang 'Diamonds Are a Girl's Best Friend' on Broadway in 1949, four years before Marilyn Monroe filmed it?

Carol Channing became a star as the gold-digging Lorelei Lee, but when Hollywood filmed the show without her the role came to be identified with Marilyn Monroe instead.

Which Australian singer-songwriter wrote the lyrics to Rihanna's 2012 hit 'Diamonds' in a reported 14 minutes?

Sia Furler recorded a guide vocal that Rihanna followed so exactly that, when a producer played Sia the finished track, she thought the voice on it was still her own.

The Koh-i-Noor was recut on Prince Albert's orders after its dull cut disappointed crowds at which 1851 London event?

The Great Exhibition crowds found it so dull that Punch dubbed it the 'Mountain of Darkness'; the recut of 1852 made it sparkle but cost it more than 40% of its weight.

Hong Kong tycoon Joseph Lau paid a record $48.4m in 2015 for the 12-carat 'Blue Moon' and renamed it after whom?

His daughter Josephine, then seven, also lent her name to a 16-carat pink diamond Lau had bought the day before for $28.5m, duly renamed the Sweet Josephine.

Queen Elizabeth II revealed in 1958 that her family called the Cullinan III and IV brooch by what nickname?

Granny's Chips came out on a 1958 visit to the Amsterdam firm that had cut the stone, where the Queen unpinned the brooch and handed it to the elderly Louis Asscher to examine.

The Star of South Africa, swapped by a shepherd for 500 sheep, set off the diamond rush that built which city?

Kimberley grew out of the 1871 'New Rush' camp the find inspired; the shepherd's full price was 500 sheep, 10 oxen and a horse, and the buyer resold the stone for £11,200.

Diamond conducts heat about five times better than which metal, the most thermally conductive of all the metals?

Silver, the best of the metals at carrying heat, still trails diamond fivefold, which is why a jeweller's thermal probe can tell a real stone from most imitations in seconds.

Which French chemist burned a diamond with sunlight through a lens in 1772 and found it gave off carbon dioxide?

Antoine Lavoisier saw the likeness to burning charcoal but drew no conclusion; in 1797 Smithson Tennant showed a diamond yields as much of the gas as the same weight of charcoal, so the gem is pure carbon.

Which gem lab devised the 'four Cs' of cut, clarity, colour and carat weight as a diamond grading standard?

GIA, the Gemological Institute of America founded in 1931, also introduced the D-to-Z colour scale, which starts at D to break from the older A, AA and AAA labels.

In 2012 roughly 84% of the world's rough diamonds passed through which European city's 'Square Mile' beside its Central Station?

Antwerp's district was also the scene of the 2003 'heist of the century', when thieves cracked a vault beneath it and took at least $100 million in diamonds, gold and jewellery, most of it never recovered.

Surat, a city that cuts and polishes about nine in every ten of the world's diamonds, is in which country?

India won the work on cost: labour-intensive cutting and polishing drifted away from Europe's old diamond centres to its lower-wage workshops.

The Argyle mine, which closed in 2020 after supplying over 90% of the world's pink diamonds, was in which country?

Australia's Argyle pit mostly yielded brown stones once fit only for industry, so its owner spent years rebranding them as 'champagne' and 'cognac' diamonds.

Which country's Karowe mine produced both the 1,109-carat Lesedi La Rona in 2015 and a 2,492-carat stone in 2024?

Botswana's Karowe pit, run by Canada's Lucara, found a trio of 300-carat-plus stones in a single week of November 2015; Graff later cut the biggest into a 302-carat emerald cut and 66 smaller gems.

Ekati, Canada's first diamond mine, opened near Lac de Gras, 200 km south of the Arctic Circle, in which region?

The Northwest Territories find capped almost ten years of prospecting by geologists Chuck Fipke and Stewart Blusson, and set off one of the largest staking rushes in mining history.

Lady Gaga wore which jeweller's 128-carat yellow diamond to the 2019 Oscars, only the third person ever to put it on?

Tiffany & Co. had let only Mary Whitehouse at a 1957 ball and Audrey Hepburn, in 1961 publicity shots for Breakfast at Tiffany's, wear it before; Beyoncé became the fourth in a 2021 campaign.

A gang ram-raided which London attraction in 2000 for a 203-carat De Beers gem, unaware police had planted replicas?

The Millennium Dome gang smashed in on a digger and meant to flee by speedboat down the Thames, but armed police were waiting behind a false wall and dressed as cleaners.

Which company's Tracy Hall made the first commercially viable synthetic diamonds in 1954 with a 'belt press'?

General Electric made a fortune from the process and rewarded Hall with a $10 savings bond; disheartened, he left within a year for Brigham Young University.

Which Danish jewellery chain said in May 2021 it would phase out mined diamonds in favour of lab-grown?

Pandora made the switch in the wake of De Beers, long a critic of synthetics, launching its own lab-grown jewellery brand, Lightbox, in 2018.

Which diamond look-alike, grown by a Soviet 'skull crucible' method and mass-produced since 1976, is the commonest fake?

Cubic zirconia melts at about 2,750°C, too hot even for a platinum crucible, so the Soviet team melted it inside a cooled crust of its own powder, the 'skull'.

Labs beat Earth's core pressure by squeezing a sample between two diamonds in a cell named for which smith's tool?

Anvil cells were pioneered at the US National Bureau of Standards, whose scientists got their diamonds free: stones that customs officers had confiscated from smugglers.

BPM 37093, nicknamed after a Beatles song because its crystallised core is one vast diamond, is what kind of star?

A white dwarf nicknamed Lucy, after 'Lucy in the Sky with Diamonds': astronomers read its pulsations in 2004 and concluded that its carbon core had crystallised.

Which 100-km Siberian crater may hold Earth's largest diamond deposit, trillions of carats from an asteroid strike?

Popigai's impact turned graphite in the ground to diamond in an instant, but the stones are mostly under 2 mm across: useful to industry, worthless as gems.

Marcel Tolkowsky's 1919 book Diamond Design fixed the 'ideal' proportions of the brilliant cut in which shape?

Round brilliants owe their proportions to his maths: he traced light through the stone to find the angles that return the most brilliance and fire, and today's cutting standards still build on them.

Which country's king received the 545-carat Golden Jubilee, long the largest cut diamond, for 50 years on the throne?

Thailand's King Bhumibol received a stone De Beers had treated as a test piece: cutters used the flawed brown rough to try out tools meant for the flawless Centenary Diamond.

Augustus III bought the largest natural green diamond known at Leipzig in 1742; which city's Green Vault displays it?

Dresden's green stone escaped the 2019 Green Vault burglary by luck: it was away on loan to the Metropolitan Museum of Art in New York when the thieves broke in.

Which family's 80-year control of De Beers ended in 2011 when Anglo American bought its 40% stake for $5.1bn?

Oppenheimer patriarch Ernest had founded Anglo American himself in 1917, so the family ended its reign by selling De Beers to the mining house it had created.