50 Fun Facts About Emerald

Emerald is a green variety of which mineral?

The same mineral yields blue, pink and yellow gems when other trace elements are present.

Trace amounts of which element are most often responsible for an emerald's green colour?

Vanadium can also do the job, and iron shifts the hue toward blue or yellow.

Emerald is the traditional birthstone for which month?

Alchemical lore also claimed the stone counteracted poison and would blind a venomous animal that looked at it.

Which zodiac sign is emerald traditionally associated with?

Older lore also credited the stone with curing epilepsy and strengthening memory.

What is the hardness of emerald on the Mohs scale?

Despite that hardness, most emeralds are so full of inclusions that their toughness is rated poor.

Which country is historically the world's largest producer of emeralds?

Its classic mining districts produce stones prized above all for their intense colour.

Which African country is the world's second-biggest emerald producer?

Its Kagem mines near Kitwe supplied about a fifth of gem-quality output in 2004, with stones that tend to be cleaner and bluer than Colombian ones.

The word emerald ultimately derives from a Greek word meaning what?

Smaragdos passed through Latin smaragdus and Old French esmeraude before reaching English in the 14th century.

What French word, meaning garden, do gemologists use for the mossy inclusions inside an emerald?

Because each stone's inclusions are unique, they can be used to identify a particular emerald.

What substance is traditionally used to fill surface cracks in emeralds to improve their clarity?

Its refractive index is close to that of the stone, and US law requires the treatment to be disclosed at sale.

Unlike diamonds, at what magnification are emeralds graded for clarity?

An emerald with no inclusions visible to the naked eye is considered flawless.

What is the shape of the signature 'emerald cut'?

Ovals are also common, and heavily included stones are often cut as cabochons instead.

Emeralds were mined in antiquity in which country, at Mount Smaragdus, from around 1500 BC?

Rome and Byzantium worked those mines on an industrial scale; they were abandoned once the South American deposits were found.

Which Egyptian queen was said to be particularly fond of emeralds?

Ancient owners believed the stones sharpened intelligence, protected marriages and let their wearer see the future.

Which of these is one of the three main emerald mining areas in the world's top-producing country?

Coscuez and Chivor are the other two, and chemical analysis can now tell stones from each apart.

What name is given to rare Colombian emeralds with ray-like spokes of dark impurities?

The name comes from the grinding wheel used to process sugarcane in the region.

In which type of rock are Colombian emeralds primarily found?

Hydrothermal brines reacting with organic matter in the sedimentary rock supplied the colouring trace elements.

In Muisca legend, emeralds formed from the tears of which figure, now a peak guarding the emerald zone?

She and Tena lost their immortality when she was unfaithful, and the god Are turned them into crags.

Roughly what share of the world's emerald market is the top-producing country estimated to supply?

Fine Colombian stones over 50 carats can cost far more than diamonds of the same size.

How long did it take Spain to overpower the Muzo people and seize their emerald lands?

The Spanish then forced the Muzo to work the fields they had mined for centuries.

The Bahia Emerald, containing the largest single crystal ever found, weighs about how much?

The 341 kg schist-embedded stone survived Hurricane Katrina in a New Orleans warehouse and years of ownership lawsuits.

The Bahia Emerald was reported stolen in 2008 from a vault in which US state?

It was later located and a Los Angeles judge spent years sorting out competing ownership claims.

The 37.82-carat Chalk Emerald ring, recut by Harry Winston, is on display at which institution?

Clair Chalk reportedly turned the ring inward at a White House dinner so as not to upstage Queen Elizabeth II's smaller emerald.

How many pear-shaped diamonds surround the Chalk Emerald in its Harry Winston setting?

They total 15.62 carats around a stone that once centred a Maharani's necklace.

The Mogul Mughal Emerald is engraved with invocations from which branch of Islam?

Since the Mughal emperors were Sunni, it probably belonged to a courtier rather than to Aurangzeb himself.

The Mogul Mughal Emerald is held by a museum in which city?

Christie's sold the 217.80-carat stone in 2001 for over 1.5 million pounds.

Which ruler gave the Duke of Devonshire his namesake emerald in 1831?

The 1,383.93-carat stone was shown at the 1851 Great Exhibition and now sits in London's Natural History Museum.

In L. Frank Baum's original 1900 novel, why did everything in the Emerald City look green?

The Wizard's 'humbug' meant the city was no greener than any other.

Which US city has used 'The Emerald City' as its official nickname since 1982?

That is 80 years after Baum's book, so the fictional city cannot have been named for it.

Which country is nicknamed the Emerald Isle, from a poem by William Drennan?

The poem was 'When Erin First Rose'; Montserrat and Kodiak Island share the nickname.

The Emerald Buddha of Bangkok is actually carved from what?

The 66 cm statue is the sacred palladium of Thailand and is housed at Wat Phra Kaew in the Grand Palace.

Which Spanish conquistador reportedly had an emerald looted from Mexico engraved with a Bible verse?

The writer Brantome called the engraving sacrilege and blamed it for the man's later misfortunes.

What is the name of the chief goddess at a famous Madurai temple, whose idol is said to be emerald?

The temple is one of India's most famous, and its deity's name means fish-eyed.

Which blue gemstone, a sibling of emerald in the same mineral species, is named from the Latin for 'sea water'?

Its pale blue comes from iron; the deep-blue form called maxixe fades in light.

What is the pink sibling of emerald within the same mineral species called?

Sellers once marketed it as 'pink emerald', a term US trade rules no longer allow.

Which is the rarest colour of emerald's parent mineral, found almost only in Utah?

Once sold as 'red emerald', it was first described in 1904 in Juab County and owes its colour to manganese.

Early lenses ground from emerald's parent mineral gave which language its word for spectacles, 'Brille'?

Glass could not yet be made clear enough, so the mineral or rock crystal was ground instead.

Which American developed the first commercially successful process for synthesising emeralds?

His flux-grown stones contain no water and traces of vanadium, which helps labs identify them.

At what rate do Gilson's flux-grown synthetic emeralds grow on their seed crystals?

A typical seven-month run yields crystals about 7 mm thick.

Emerald is grouped with diamond, ruby and sapphire as one of the traditional what?

Colour, not clarity, is by far the most important factor when grading it.

In which Canadian territory were emeralds discovered in 1998?

In the US they have turned up in North Carolina, Montana, Nevada, Connecticut and South Carolina.

In the Hebrew Bible, an emerald (bareket) was one of the stones set in what?

Emeralds' brittleness comes from their many inclusions, even though the mineral itself is quite hard.

Which company is today's largest producer of hydrothermal synthetic emeralds?

Union Carbide's Linde Division made fully synthetic hydrothermal emeralds from 1965 to 1970.

Because most emeralds are riddled with inclusions, how is their toughness classified?

Hardness is a respectable 7.5 to 8 on the Mohs scale, but the stone chips easily.

Emerald belongs to which structural class of silicate minerals?

It typically forms alongside quartz, muscovite, albite, fluorite and tourmalines such as schorl and elbaite.

What ended emerald mining in Egypt?

The Egyptian mines had been worked on an industrial scale by the Romans, Byzantines and later Islamic rulers.

Zambia's Kagem Mines lie in the deposits of which river area, southwest of Kitwe?

The area accounted for about 20% of the world's gem-quality emerald production in 2004.

In gemstone grading, which of the 'four Cs' is normally by far the most important for an emerald?

Only medium to dark-toned stones count as emeralds; lighter ones are just called green beryl.

Which US body requires sellers to disclose when an emerald has been oil-treated?

Oiled stones are worth far less than untreated ones, and green-tinted oil is not accepted in the trade at all.

Under what names were the first commercial hydrothermal synthetic emeralds sold in the 1960s?

Made by Johann Lechleitner of Innsbruck, they were a thin emerald layer grown over natural colourless beryl.