Britain's Catherine, Duchess of Cambridge attends a ceremonial welcome for the President of Singapore Tony Tan, and his wife, at Horse Guards Parade in London October 21, 2014. The President and his wife will be guests of Queen Elizabeth during the first state visit of a Singapore President to Britain.
REUTERS/Toby Melville (BRITAIN - Tags: POLITICS ROYALS ENTERTAINMENT TPX IMAGES OF THE DAY) 

Yau, 22, gets down to his knees and proposes to his girlfriend Chen, 21, both university students and pro-democracy protesters. on a main street which they occupied, at Mongkok shopping district in Hong Kong October 5, 2014.Tens of thousands of protesters have staged sit-ins across Hong Kong over the past week, demanding the city's pro-Beijing leader Leung Chun-ying step down and calling on China to reverse its decision to select the candidates for the city's 2017 leadership election. Chinese characters on Yau's arm read as "Leung Chun-ying, step down". REUTERS/Liau Chung-ren (CHINA - Tags: POLITICS CIVIL UNREST SOCIETY TPX IMAGES OF THE DAY) 

Zhiliang, whose fiancee was onboard Malaysia Airlines Flight MH370 which disappeared on March 8, 2014, is silhouetted at an empty house which he had planned to decorate with her for their marriage, after he showed the house during an interview with Reuters in Tianjin, August 26, 2014. Zhiliang said he will wait for his missing fiancee forever. They had planned to marry this year. Six months after Malaysia Airlines Flight MH370, with 239 mostly Chinese people on board, disappeared about an hour into a routine journey from Kuala Lumpur to Beijing March 8, loved ones of missing passengers derive what comfort they can from what's left behind after the world's greatest aviation mystery. More than two dozen countries have been involved in the air, sea and underwater search for the Boeing 777 but months of sorties failed to turn up any trace - even after narrowing the search area to the southern Indian Ocean - long after batteries on the black box voice and data recorders had gone flat. Picture taken August 26, 2014. REUTERS/Kim Kyung-Hoon (CHINA - Tags: ANNIVERSARY TRANSPORT DISASTER TPX IMAGES OF THE DAY)

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A ring is seen on the finger of Jessica Michibata, fiancee of McLaren Formula One driver Jenson Button, as she watches the first practice session of the Malaysian F1 Grand Prix from the pit lane at Sepang International Circuit outside Kuala Lumpur, March 28, 2014. REUTERS/Edgar Su (MALAYSIA - Tags: SPORT MOTORSPORT F1 ENTERTAINMENT)

Cast member Amber Heard and her fiance, actor Johnny Depp, pose at the premiere of "3 Days to Kill" in Los Angeles, California February 12, 2014. The movie opens in the U.S. on February 21. REUTERS/Mario Anzuoni (UNITED STATES - Tags: ENTERTAINMENT) 

Women gather as they celebrate the future engagement of resident Saray Gabarri outside her house in Madrid's Spanish gypsy settlement of Puerta de Hierro July 31, 2012. Fifty-four families have been living in Puerta de Hierro, on the banks of the Manzanares river for over 50 years. Since the summer of 2010, the community has been subject to evictions on the grounds that the dwellings are illegal. Families whose houses have been demolished, move in with relatives whose houses still remain while the debris keeps piling up around them as more demolitions take place. Picture taken July 31, 2012. REUTERS/Susana Vera (SPAIN - Tags: SOCIETY)

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A ring on the finger of producer and cast member Jennifer Garner, who is pregnant with her third child and married to actor Ben Affleck, is seen as she arrives at a screening of the film "Butter" during AFI Fest 2011 in Hollywood November 6, 2011. REUTERS/Danny Moloshok (UNITED STATES - Tags: ENTERTAINMENT) 

TV personality Kim Kardashian's wedding ring is pictured during an interview with Reuters in Dubai October 13, 2011. Kardashian is in the United Arab Emirates to launch the opening of a milkshake bar at the Dubai Mall on October 14. REUTERS/Jumana El Heloueh (UNITED ARAB EMIRATES - Tags: ENTERTAINMENT) 

U.S. Navy Counselor 1st Class Luz Bautista, 30, who is four-months pregnant, (R) prepares dinner with her fiancee U.S. Navy Petty Officer 2nd Class Alejandra Schwartz, 24, at their home in San Diego, California September 21, 2011. The 'Don't Ask, Don't Tell' law, which prevented serving US military personnel from disclosing that they were gay, was abolished Tuesday. However, the military does not recognize same-sex marriage, and same-sex couples do not have the same benefits, or protection from being posted separately that heterosexual married couples in the military have. Bautista is being posted to Illinois for three years on Monday. The couple plans to pass the new baby to each other every few months, so she bonds with both mothers. But Bautista doesn't know when it will be possible for her to live with Alejandra and their six-year-old daughter Destiny again. Picture taken September 21, 2011. REUTERS/Lucy Nicholson (UNITED STATES - Tags: MILITARY POLITICS SOCIETY) 

Shantel Jackson, the fiancee of undefeated welterweight boxer Floyd Mayweather Jr. of the U.S., shows her engagement ring during Mayweather's media workout at the Mayweather Boxing Club in Las Vegas, Nevada September 6, 2011. Mayweather challenges WBC welterweight champion Victor Ortiz, also of the U.S., for the WBC title at the MGM Grand Garden Arena in Las Vegas on September 17. REUTERS/Steve Marcus (UNITED STATES - Tags: SPORT BOXING ENTERTAINMENT) 

Kim Kardashian's wedding ring is pictured as she arrives at the 2011 MTV Video Music Awards in Los Angeles August 28, 2011. REUTERS/Danny Moloshok (UNITED STATES - Tags: ENTERTAINMENT SOCIETY) (MTV-ARRIVALS) 

The wedding ring and the engagement ring are seen on Britain's Catherine, Duchess of Cambridge, at Buckingham Palace in London. REUTERS/Ian West/Pool (BRITAIN - Tags: ENTERTAINMENT SOCIETY ROYALS) 

A sales representative poses with a made-in-China replica of the British royal engagement ring at a British brand accessories store in Hong Kong April 28, 2011. The ring, which costs HK$85 ($10.90), is a replica of the original engagement ring given by Britain's Prince William to his fiance Kate Middleton. The couple will be getting married on Friday. REUTERS/Bobby Yip (CHINA - Tags: SOCIETY ENTERTAINMENT ROYALS) 

Manabu Yonezawa shows a pair of engagement rings which he uncovered in the mud while helping to salvage items from the bakery where he worked in Ofunato, nearly two weeks after the area was devastated by a magnitude 9.0 earthquake and tsunami, March 23, 2011. One ring, slightly dented from the ordeal, is engraved with the name "Yoko" and a date and the other ring is engraved with "Keep on Loving". REUTERS/Issei Kato (JAPAN - Tags: DISASTER ENVIRONMENT) 

The official photo of the engagement of Prince Albert II of Monaco and his fiancee Charlene Wittstock is displayed in a shop in Monaco March 3, 2011. Prince Albert II and Charlene Wittstock will marry at the Monaco palace on July 1, 2011. REUTERS/Eric Gaillard (MONACO - Tags: ROYALS TRAVEL SOCIETY) 

Britain's Prince William and his fiancee Kate Middleton listen to speeches during their visit to St. Andrews University in Fife, Scotland February 25, 2011. The couple made their second official visit together since announcing their engagement in November to St. Andrews University to launch its 600th anniversary celebrations. REUTERS/Toby Melville (BRITAIN - Tags: EDUCATION ROYALS) 

Souvenir postcards on sale to mark the forthcoming wedding of Britain's Prince William and Catherine Middleton are seen at a shop in London, January 27, 2011. Prince William, son of heir-to-the-throne Prince Charles and the late Diana, is to marry fiancee Kate Middleton at London's Westminster Abbey on April 29. REUTERS/Paul Hackett (BRITAIN - Tags: ROYALS ENTERTAINMENT SOCIETY) 

A souvenir picture frame is seen at a shop in London, January 27, 2011. Prince William, son of heir-to-the-throne Prince Charles and the late Diana, is to marry fiancee Kate Middleton at London's Westminster Abbey on April 29. REUTERS/Paul Hackett (BRITAIN - Tags: ROYALS ENTERTAINMENT SOCIETY) 

Kate Bevan, a lookalike of Kate Middleton, the fiancee of Britain's Prince William, poses for a photograph with a knitted toy inspired by the forthcoming royal wedding, at a toy fair, in London January 25, 2011. REUTERS/Andrew Winning (BRITAIN - Tags: ENTERTAINMENT BUSINESS SOCIETY) 

A combination picture shows a Chinese made replica of the British royal engagement ring (L) displayed at a jewellery factory in Yiwu, Zhejiang province January 12, 2011, and the original engagement ring given by Britain's Prince William to his fiance Kate Middleton in London on November 16, 2010. Chinese manufacturers are cashing in on the British royal wedding craze as they churn out tens of thousands of replica royal engagement rings for the world. To match Reuters Life! BRITAIN ROYAL/RING REUTERS/Carlos Barria/Paul Hackett (CHINA - Tags: SOCIETY ROYALS IMAGES OF THE DAY) 

An employee holds a replica of the British royal engagement ring at a jewellery factory in Yiwu, Zhejiang province January 12, 2011. Chinese manufacturers are cashing in on the British royal wedding craze as they churn out tens of thousands of replica royal engagement rings for the world. To match Reuters Life! BRITAIN ROYAL/RING REUTERS/Carlos Barria (CHINA - Tags: SOCIETY ROYALS) 

Replicas of the British royal engagement ring are seen at a jewellery factory in Yiwu, Zhejiang province January 12, 2011. Chinese manufacturers are cashing in on the British royal wedding craze as they churn out tens of thousands of replica royal engagement rings for the world. To match Reuters Life! BRITAIN ROYAL/RING REUTERS/Carlos Barria (CHINA - Tags: SOCIETY ROYALS) 

An employee packages replicas of the British royal engagement ring at a jewellery factory in Yiwu, Zhejiang province January 12, 2011. Chinese manufacturers are cashing in on the British royal wedding craze as they churn out tens of thousands of replica royal engagement rings for the world. To match Reuters Life! BRITAIN ROYAL/RING REUTERS/Carlos Barria (CHINA - Tags: SOCIETY ROYALS IMAGES OF THE DAY) 

Zara Phillips displays her engagement ring as she stands with her fiance Mike Tindall at their home in Gloucestershire, south-west England December 21, 2010. Phillips, the granddaughter of Britain's Queen Elizabeth, is to marry rugby player Tindall, the royal family said on Tuesday. REUTERS/Tim Ireland/Pool (BRITAIN - Tags: ROYALS ENTERTAINMENT SPORT RUGBY) 

A mug commemorating the engagement of Britain's Prince William to Kate Middleton is pictured at the Prince William Pottery Company in Liverpool, northern England November 18, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SOCIETY ROYALS) 

Mugs commemorating the engagement of Britain's Prince William to Kate Middleton move along a conveyor belt at the Prince William Pottery Company in Liverpool, northern England November 18, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SOCIETY ROYALS) 

Mugs commemorating the engagement of Britain's Prince William to Kate Middleton move along a conveyor belt at the Prince William Pottery Company in Liverpool, northern England November 18, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SOCIETY ROYALS) 

Britain's Prince William and his fiancee Kate Middleton (L) pose for a photograph in St. James's Palace, central London November 16, 2010. Britain's Prince William is to marry his long-term girlfriend Kate Middleton next year, after an on-off courtship lasting nearly a decade, bringing months of speculation about his intentions to an end. REUTERS/Paul Hackett (BRITAIN - Tags: ENTERTAINMENT SOCIETY ROYALS) 

Kate Middleton shows her engagement ring given by her fiance Britain's Prince William in London November 16, 2010. Britain's Prince William is to marry his long-term girlfriend Kate Middleton next year, after an on-off courtship lasting nearly a decade, bringing months of speculation about his intentions to an end. REUTERS/Arthur Edwards/POOL (BRITAIN - Tags: ENTERTAINMENT SOCIETY ROYALS PROFILE) 

REFILE - A pair of photographs show Kate Middleton (L), fiance of Britain's Prince William posing in London November 16, 2010 and William's mother Diana, Princess of Wales, wearing the same engagment ring in London in an August 28, 1996 file photo. Britain's Prince William is to marry his long-term girlfriend Kate Middleton next year, after an on-off courtship lasting nearly a decade, bringing months of speculation about his intentions to an end. REUTERS/Paul Hackett/Dan Chung (BRITAIN - Tags: ENTERTAINMENT SOCIETY ROYALS PROFILE) 

Hungarian aerobatic pilot Zoltan Veres flies above Lake Balaton during the Grand Aero Challenge in Balatonfured, 150 km (93 miles) west of Budapest July 2, 2009. REUTERS/Laszlo Balogh (HUNGARY ANIMALS TRANSPORT SOCIETY IMAGES OF THE DAY) 

An engagement ring is displayed at a jewellery store in Tokyo June 2, 2009. Japanese men are increasing spending less on diamond rings or not buying them at all, a reflection of the country's sluggish economy and changing view on courtship and marriage. Picture taken June 2, 2009. REUTERS/Yuriko Nakao (JAPAN BUSINESS SOCIETY) 

A man puts an engagement ring on a woman's finger during a photo opportunity at a jewellery store in Tokyo June 2, 2009. Japanese men are increasingly spending less on diamond engagement rings or not buying them at all, a reflection of the country's sluggish economy and changing views on courtship and marriage. Picture taken June 2, 2009. REUTERS/Yuriko Nakao (JAPAN BUSINESS SOCIETY) 

An engagement ring is displayed at a jewellery store in Tokyo June 2, 2009. Japanese men are increasingly spending less on diamond engagement rings or not buying them at all, a reflection of the country's sluggish economy and changing views on courtship and marriage. Picture taken June 2, 2009. REUTERS/Yuriko Nakao (JAPAN BUSINESS SOCIETY) 

The Bandra-Worli sea link is seen over the Arabian Sea off the coast of Mumbai April 28, 2009. The first phase of the construction of the Bandra-Worli sea link, an eight-lane, cable-stayed bridge above the Arabian sea was completed on Tuesday and it will be opened to commuters later next month. The 4.7 km bridge, which links Mumbai's Worli and Bandra areas is expected to ease out the traffic congestion between these two areas. REUTERS/Arko Datta (INDIA BUSINESS TRANSPORT) 

Sweden's Crown Princess Victoria shows her engagement ring during a news conference at the Royal Palace in Stockholm February 24, 2009. Victoria, 31, the next in line to Sweden's throne, has become engaged to her long-standing boyfriend, 35-year-old gym owner Daniel Westling, the Swedish royal court said on Tuesday. REUTERS/Bob Strong (SWEDEN) 

Sweden's Crown Princess Victoria shows her engagement ring during a news conference after her engagement to Daniel Westling (L) was announced at the Royal Palace in Stockholm February 24, 2009. The royal court said the wedding will take place early summer next year. REUTERS/Bob Strong (SWEDEN) 

Miss Universe 2005 Natalie Glebova of Canada is seen with a ring during a news conference to announce her engagement to Thai tennis star Paradorn Srichaphan in Bangkok April 24, 2007. REUTERS/Adrees Latif (THAILAND) 

Tokyo metropolitan government worker Yoshiki Kuroda, who will marry Japanese Princess Sayako, daughter of Emperor Akihito, arrives with his mother Sumiko Kuroda at the Imperial Palace in Tokyo for a formal announcement of the date of their matrimony October 5, 2005. The government announced earlier in the year that the couple is to marry on November 15. REUTERS/Yuriko Nakao PP05100038 

U.S. actress Katie Holmes' engagement ring is seen as she arrives at the UK premier of "War of the Worlds" in London. U.S. actress Katie Holmes' engagement ring is seen as she arrives at the UK premier of U.S. actor Tom Cruise's latest movie "War of the Worlds" by U.S. director Stephen Spielberg in Leicester Square, London, June 19, 2005. Cruise announced his engagement to actress-girlfriend Holmes at the Paris premier on Friday ending weeks of speculation that the Hollywood couple would wed. REUTERS/Mike Finn-Kelcey 

Singer Christina Aguilera displays her engagement ring at the opening of the Roberto Cavalli Boutique in Beverly Hills. Singer Christina Aguilera displays her engagement ring to photographers as she arrives as a guest at the opening of Italian fashion designer Roberto Cavalli's Boutique in Beverly Hills February 15, 2005. Aguilera recently became engaged to music executive Jordan Bratman. REUTERS/Fred Prouser Pictures of the Month February 2005 PP05080045 Pictures of the Year 2005 

Parker Bowles' engagement ring is seen as she makes her first public appearance with Britain's Prince Charles since they announced their wedding engagement at Windsor Castle. Camilla Parker Bowles shows off her diamond engagement ring as she makes her first public appearance with Britain's Prince Charles since they announced their wedding engagement, during a pre-scheduled function at Windsor Castle near London February 10, 2005. British heir to the throne Prince Charles announced on Thursday he will marry long-time lover Camilla Parker Bowles, the woman blamed for destroying his "fairytale" marriage to the late Princess Diana. REUTERS/John Stillwell/Pool Pictures of the month February 2005