Gemstones Trivia
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7correct to beat the crowd
99 free Gemstones trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Gemstones are geology you can wear, and almost every famous one carries a story: a stone that powered the first laser, a crown jewel that is not what its name says, a museum heist solved by a tip-off, and a pigment so precious that painters saved it for the Virgin Mary. These 99 questions range across the precious four and the semi-precious crowd: what gives each stone its colour, where the finest ones are mined, how birthstones were standardised, which gems are grown in a lab, and the famous diamonds, sapphires and pearls that have passed through royal and rather less royal hands. Most are pitched for a pub table or a family quiz night, with a harder tier for collectors and jewellers. Play on your phone with instant answers and explanations, or print the set for a quiz night, a classroom or a jewellery-party icebreaker.
30 of 99 questions with answers and explanations. Play the quiz
Q 01Which purple stone, its Greek name meaning 'not drunk', was a 'cardinal' gem until Brazilian finds made it common?
Amethyst
Amethyst was worn by ancient Greek drinkers as a charm against the effects of wine, and it stayed as costly as emerald until Brazil's large deposits were discovered.
Q 02Which blue-violet gem, found in 1967 in the Mererani Hills, did Tiffany & Co. rename and launch in 1968?
Tanzanite
Tanzanite is the name Tiffany & Co. gave blue-violet zoisite in 1968, judging the mineral's real name too unappealing to sell. It is mined commercially in just one small area on Earth, near Mount Kilimanjaro.
Q 03Which aluminium-oxide mineral goes by one gem name when red and another in every other colour?
Corundum
Corundum is prized as a jewel when clear and coloured, yet its dull black form is emery, crushed for the grit on emery boards because the mineral rates 9 on the Mohs hardness scale.
Q 04Which word comes from the Greek for amber, a resin that attracts bits of straw once it is rubbed?
Electricity
Electricity, electric and their relatives all descend from elektron, the Greek for amber, which bears a static charge when rubbed. Persian called the stone kah-ruba, 'straw-snatcher', and that word became the Arabic for electricity too.
Q 05Which gem, classed as a mineraloid because it has no crystal structure, did NASA announce in 2008 it had found on Mars?
Opal
Opal is hydrated silica, a telltale sign of water: NASA said the deposits its orbiter found showed that Mars stayed wet a billion years longer than scientists had believed.
Q 06The first working laser, built by Theodore Maiman in 1960, used a synthetic rod of which gem as its light source?
Ruby
Ruby, grown synthetically, was the gain medium in the laser Maiman fired at Hughes Research Laboratories on 16 May 1960. A xenon flashtube pumps the rod with light, and the same trace atoms that colour the crystal red do the lasing.
Q 07Which royal bride chose her own 12-carat oval sapphire ring from Garrard, the ring William gave Catherine in 2010?
Diana Spencer
Diana Spencer picked the ring herself in 1981: a 12-carat oval sapphire ringed by 14 diamonds. William said that giving it to Catherine was his way of making sure his mother 'didn't miss out' on the day.
Q 08Which mineral did the ancient Greeks call 'krystallos', thinking its clear form was ice frozen too hard to melt?
Quartz
Quartz was krystallos, from kryos, 'icy cold', because Theophrastus and others believed clear rock crystal was permanently frozen water, an idea Pliny the Elder still held. Every 'crystal' in English descends from that mistake.
Q 09A pearl is built up in layers of which iridescent material, the same stuff that lines a mollusc's shell?
Nacre
Nacre, better known as mother of pearl, is laid down by the same living process whether it coats the shell's interior or wraps an intruder into a pearl. It is calcium carbonate, mostly aragonite, deposited in concentric layers.
Q 10Which country, home to the Muzo mines, has historically been the world's largest producer of emeralds?
Colombia
Colombia's Muzo district also yields rare 'trapiche' emeralds, crossed by six dark spokes and named after the Spanish for a sugar mill because the pattern looks like its grinding wheel.
Q 11The 423-carat Logan Sapphire, the size of a chicken egg, came from which island, original home of the padparadscha?
Sri Lanka
Sri Lanka produced the Logan Sapphire, which Rebecca Guggenheim received as a Christmas and anniversary present and gave to the Smithsonian in 1960. A 1997 GIA report found its blue natural, with no heat treatment.
Q 12Which pale-blue gem shares the beryl family with emerald, its largest cut example being Brazil's Dom Pedro?
Aquamarine
Aquamarine takes its name from the Latin for sea water, and sailors once carried it as a charm against shipwreck. The Dom Pedro is a 14-inch obelisk carved by Bernd Munsteiner, now at the Smithsonian.
Q 13Which green gem, an August birthstone, turns up inside pallasite meteorites as well as in volcanic basalt?
Peridot
Q 21Which pigment, ground from lapis lazuli, did Renaissance painters often reserve for the Virgin Mary's clothing?
Ultramarine
Ultramarine, ground from imported lapis, was used by Masaccio, Titian and Vermeer, and has even turned up in the dental tartar of a woman buried at a medieval German convent, most likely from licking her brush.
Q 22Pliny the Elder claims which queen dissolved a pearl worth millions of sesterces in vinegar to win a dinner-party bet?
Cleopatra
Cleopatra's stunt has real chemistry behind it: pearls are mostly calcium carbonate, which the acetic acid in vinegar turns into calcium acetate and carbon dioxide, though not as instantly as Pliny's tale has it.
Q 23Moissanite, first found in 1893 in rock from Arizona's Meteor Crater, is a natural form of which compound?
Peridot is gem-quality olivine, and large clean crystals are rare on Earth because the mineral breaks down so readily at the surface. A few crystals from meteorites are big enough to facet as cut gems.
Q 14Which January birthstone, really a family of minerals, is said to take its name from the pomegranate and its red seeds?
Garnet
Garnet has been worn as a gem for thousands of years. Prospectors also follow certain garnets through soil and streams, because the same deep volcanic rock that carries diamonds brings them to the surface.
Q 15Diamond is metastable at room temperature and pressure, converting at a negligible rate into which other form of carbon?
Graphite
Graphite is the stable form of carbon under everyday conditions, but diamond converts to it at a negligible rate, so the change is academic. In graphite the atoms bond in planes that slip past each other, which is why it is soft.
Q 16Which cut polishes a gem into a smooth dome instead of facets, the way to show a star or a cat's eye?
Cabochon
Cabochon, from the Middle French for 'head', was the usual way to finish a gem before faceting developed, and it is still the cut for opaque stones. The dome shows the star in a star sapphire that faceting would hide.
Q 17A diamond's rainbow flashes, which jewellers call 'fire', come from which optical property of the stone?
Dispersion
Dispersion, the splitting of white light into colours, is what the trade calls fire. A cutter balances it against brilliance: a smaller table facet shows more fire but returns less white light.
Q 18Jet, the black stone Queen Victoria wore in mourning for Prince Albert, is a form of what?
Fossil wood
Fossil wood, squeezed over millions of years into lignite, the lowest rank of coal, is what jet is, commonly from trees akin to the Chilean pine. Victorian mourning made it the fashion, and it gave English the phrase 'jet-black'.
Q 19Red 'precious' coral, the Corallium rubrum carved into jewellery since antiquity, grows mainly in which sea?
Mediterranean
Mediterranean waters are the main home of Corallium rubrum, which grows on dark rocky seabeds in the depths or in caves. Coral jewellery turns up in prehistoric European burials, and the material is too soft to facet, so it is cut as beads.
Q 20The Sar-i Sang mines, which have supplied lapis lazuli for more than 6,000 years, lie in which modern country?
Afghanistan
Afghanistan's Badakhshan province supplied the lapis in Tutankhamun's funeral mask and served the Persian and Mesopotamian civilisations, and its mines are still producing. Sar-i Sang sits in the Kokcha River valley.
Silicon carbide
Silicon carbide crystals from the crater were first taken for diamonds by Henri Moissan, who identified them correctly only years later. Edward Acheson had already made the compound artificially in 1891, two years before the natural find.
Q 24Which Washington socialite bought the Hope Diamond from Pierre Cartier in 1911, curse stories and all?
Evalyn Walsh McLean
Evalyn Walsh McLean bought it after Cartier's slow-burn presentation; the tales of a cursed origin were most likely invented in the early 1900s to add mystique and lift the price.
Q 25The Regent Diamond, mined in India and cut in London, was set in the sword of which French ruler?
Napoleon
Napoleon wore the Regent on his sword, where Louis XV had worn it in his coronation crown. It was stolen with the other crown jewels in 1792, recovered, and went on show in the Louvre in 1887.
Q 26Coober Pedy, a gem-mining town where many residents live in underground 'dugouts', lies in which country?
Australia
Australia's Coober Pedy dates from 1915, when a boy in his father's gold-prospecting party found the first gems there. Residents dug their homes into the hills to escape the scorching desert heat.
Q 27Which of jade's two minerals did China carve for millennia before Burmese jadeite arrived in quantity around 1800?
Nephrite
Nephrite reached China's carvers mainly from Khotan, on the Silk Road. Its name means 'kidney stone', from the old belief that wearing it eased pain in the kidneys, the same idea behind the Spanish phrase that gave English 'jade'.
Q 28Alexandrite, green by daylight and red under incandescent light, is a rare variety of which mineral?
Chrysoberyl
Chrysoberyl is a different mineral from beryl despite the name. Alexandrite turned up in Russia's Urals in the 1830s and was named for the young heir Alexander II, its red and green echoing the colours of the Russian empire.
Q 29Which Myanmar valley, forced open by the British in 1886, was for centuries the main source of 'pigeon's blood' stones?
Mogok
Mogok has produced sought-after stones for more than five centuries. The finest seem to glow because the crystal fluoresces, re-emitting red light on top of its own colour, the look the trade calls 'pigeon's blood'.
Q 30Neon-blue 'Paraíba' tourmaline, named after a Brazilian state, owes its electric colour mainly to which metal?
Copper
Copper gives the neon colour, in stones first found in the late 1980s. Labs now apply 'Paraíba' to copper-bearing tourmaline from Nigeria and Mozambique too, because the name has come to mark the metal, not the place.