Getting your questions ready
Getting your questions ready
Beat the crowd
10 questions No timer
40 free Diamonds trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Diamonds are carbon that took a few billion years and a violent volcanic lift to reach a jeweller's window, and almost everything about them — the price, the ring, the slogan — was shaped by people as much as by geology. The 40 questions cover how the stone forms and is graded, the celebrated gems and the monarchs, tycoons and film stars who owned them, the mines and the company that ran the trade for a century, conflict stones and the certification meant to stop them, lab-grown rivals and fakes, and diamonds in song, film and advertising. It suits a pub quiz round, a jewellery-trade icebreaker or anyone who has ever wondered what the four Cs actually measure. Play on your phone with instant answers and a one-line explanation for each, or print it for the table.
30 of 40 questions with answers and explanations. Play the quiz
Q 01While a decoy sailed under guard by steamer, how did the 3,106-carat Cullinan rough reach London in 1905?
By registered post
By registered post, in a plain box: detectives shadowed the RMS Kenilworth Castle and its ceremonially guarded parcel, and even the captain never knew his cargo was the decoy.
Q 02Harry Winston sent the Hope Diamond to the Smithsonian in 1958 wrapped in plain brown paper; how much was the postage?
$2.44
$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.
Q 03Which French queen's name was wrecked by the 1785 Affair of the Diamond Necklace, a con she never took part in?
Marie Antoinette
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.
Q 04Which 1985 Madonna video restages Marilyn Monroe's pink-gown number from Gentlemen Prefer Blondes, suitors and all?
Material Girl
Material Girl copies the Gentlemen Prefer Blondes staging, Madonna ringed by tuxedoed suitors, intercut with a Hollywood director trying to win the actress's heart.
Q 05Blood Diamond (2006), with Leonardo DiCaprio as a Rhodesian smuggler, is set in which country's 1999 civil war?
Sierra Leone
Sierra Leone's war pits government loyalists against insurgents, and DiCaprio's Danny Archer is jailed in Freetown for trying to run diamonds into Liberia.
Q 06Which US state's Crater of Diamonds park lets visitors keep any gem they find, on the field that yielded the Uncle Sam?
Arkansas
Arkansas bought the Murfreesboro site in 1972; the 40.23-carat Uncle Sam, dug there in 1924, remains the largest diamond ever found in the United States.
Q 07On Friedrich Mohs's scratch-hardness scale, diamond sits at which number, a single step above corundum?
10
10 was set arbitrarily as the top of the scale, yet in absolute hardness diamond is about four times harder than corundum, which rates 9.
Q 08The carat used to weigh diamonds is named after the seed of which tree, long used by gem traders as a weight?
Carob
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.
Q 09Who founded De Beers Consolidated Mines in 1888, bankrolled by Alfred Beit and the Rothschild bank?
Cecil Rhodes
Cecil Rhodes formed it by merging his claims with rival Barney Barnato's, and served as the company's first secretary and chairman.
Q 10From 1888 until the early 2000s, roughly what share of the world's rough diamond distribution did De Beers control?
80–85%
80–85% was enough to count as a monopoly, and the grip only loosened in the 21st century as Canadian and Australian producers sold outside the De Beers channel; by 2000 its share had slipped to about 63%.
Q 11De Beers adverts told men what slice of income to spend on a ring; how much did the 1980s Japanese version ask?
Three months'
Three months' income was the Japanese figure against two in America; the whole idea that a man should spend a set fraction of his annual income on a ring began in De Beers marketing of the mid-20th century.
Q 12Grace Kelly wore her real Cartier engagement ring from Prince Rainier on screen in which 1956 film, her last?
High Society
High Society, a musical remake of The Philadelphia Story, reached cinemas shortly after her wedding and was her final professional appearance.
Q 13Who bought Elizabeth Taylor a 69-carat pear-shaped diamond in 1969, a day after Cartier outbid him for it at auction?
Q 21Who focused sunlight through a lens to burn a diamond in oxygen in 1772, proving it is pure carbon?
Antoine Lavoisier
Antoine Lavoisier found the only product of the combustion was carbon dioxide; the English chemist Smithson Tennant repeated and extended the experiment in 1797.
Q 22Which gem lab devised the 'four Cs' of cut, clarity, colour and carat weight as a diamond grading standard in 1953?
GIA
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.
Q 23Roughly 84% of the world's rough diamonds pass through which European city's 'Square Mile' beside its Central Station?
Antwerp
Richard Burton
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.
Q 14Who first sang 'Diamonds Are a Girl's Best Friend' on Broadway in 1949, four years before Marilyn Monroe filmed it?
Carol Channing
Carol Channing introduced the Jule Styne and Leo Robin number in the original Gentlemen Prefer Blondes, and recorded it again in 1974 for the revised musical Lorelei.
Q 15Which Australian singer-songwriter wrote the lyrics to Rihanna's 2012 hit 'Diamonds' in a reported 14 minutes?
Sia Furler
Sia Furler joined producers Benny Blanco and Stargate at the session, and Rihanna copied her demo vocal so closely that Sia reportedly thought her own recording had been released.
Q 16The Koh-i-Noor was recut on Prince Albert's orders after its dull cut disappointed crowds at which 1851 London event?
The Great Exhibition
The Great Exhibition showing was such a let-down that Punch mocked the stone; Coster's 38-day recut then shrank it from 186 old carats to 105.6.
Q 17Hong Kong tycoon Joseph Lau paid a record $48.4m in 2015 for the 12-carat 'Blue Moon' and renamed it after whom?
His daughter
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.
Q 18Queen Elizabeth II revealed in 1958 that her family called the Cullinan III and IV brooch by what nickname?
Granny's Chips
Granny's Chips slipped out during a state visit to the Netherlands, home of the Asscher firm that had cleaved and polished the rough stone fifty years earlier.
Q 19What did farmer Schalk van Niekerk pay a Griqua shepherd in 1869 for the rough Star of South Africa?
500 sheep, 10 oxen, a horse
500 sheep, 10 oxen, a horse bought an 83.5-carat rough that Van Niekerk sold on for £11,200, and the find set off the rush that dug the Big Hole.
Q 20Diamond conducts heat about five times better than which metal, the most thermally conductive of all the metals?
Silver
Silver trails natural diamond's 2,200 W/(m·K) by a factor of five, which is why a jeweller's thermal probe can separate a real stone from most imitations in seconds.
Antwerp's Diamantkwartier covers a few square blocks, and although the polishing has mostly moved to cheaper countries, about half the rough comes back there to be cut.
Q 24Which Gujarat city on the Tapti river cuts and polishes about nine in every ten of the world's diamonds?
Surat
Surat handles roughly 90% of the world's cutting and polishing, work that left the old European centres as their wages rose, while the city's other big trade remains textiles.
Q 25The Argyle mine, which closed in 2020 after supplying over 90% of the world's pink diamonds, was in which country?
Australia
Australia's remote north-west hosted it for 37 years, during which it also yielded champagne, cognac and rare blue stones and was at times the world's biggest diamond producer by volume.
Q 26Which country's Karowe mine produced both the 1,111-carat Lesedi La Rona in 2015 and a 2,492-carat stone in 2024?
Botswana
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.
Q 27Ekati, the first diamond mine in Canada, opened near Lac de Gras in which territory, 200 km south of the Arctic Circle?
Northwest Territories
Northwest Territories' Ekati lies 310 km north-east of Yellowknife, on pipes that geologists Chuck Fipke and Stewart Blusson discovered and kept a stake in until 2014.
Q 28Lady Gaga wore which jeweller's 128-carat yellow diamond to the 2019 Oscars, only the third person ever to put it on?
Tiffany & Co.
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.
Q 29A gang ram-raided which London attraction in 2000 for a 203-carat De Beers gem, unaware police had planted replicas?
The Millennium Dome
The Millennium Dome's riverside De Beers show held the flawless 203-carat Millennium Star, but the Flying Squad had replaced the gems and hidden 20 armed officers behind a false wall.
Q 30Which company's Tracy Hall made the first commercially viable synthetic diamonds in 1954 with a 'belt press'?
General Electric
General Electric had chased synthesis since a 1941 pact with Norton and Carborundum, and Hall's grit, squeezed in a hydraulic press at its Schenectady labs, was announced in February 1955.