Eleanor Widener's gold-plated necklace. The chain, recovered from the Titanic, has been stolen from a display at Copenhagen's Tivoli Gardens. Courtesy: Tivoli

Just like the "Heart of the Ocean," the iconic blue-diamond necklace worn by Kate Winslet in James Cameron’s 1997 epic movie, a now untraceable jewel from the Titanic is telling an intriguing story of love and loss.

A gold-plated necklace that belonged to first-class passenger Eleanor Elkins Widener of Philadelphia was stolen last Saturday from the show "Titanic – The Exhibition" at Copenhagen's Tivoli Gardens amusement park.

Known as Nellie to her friends, Eleanor was travelling with her husband George Dunton Widener (the son of the streetcar magnate Peter A.B. Widener), their 27-year-old-son Harry Elkins Widener, and two domestics – maid Amalie Gieger and manservant Edwin Keeping.

The Wideners had left Lynnewood Hall, the 110-room Georgian-style family mansion in Elkins Park, Pennsylvania, on March 13, 1912, for a brief journey to Europe.

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"I'm about to make a quick trip to England…I'm really hoping to get a number of books," Harry Elkins Widener, an avid book collector, wrote to a friend.

"We sail on Wednesday at 1 a.m. on the Mauretania and return on April 10th on the maiden voyage of the Titanic," Harry wrote on March 10th.

Indeed the family boarded the "unsinkable" Titanic at Cherbourg, France, on 10th April 1912.

On April 14th, the Wideners, one of the wealthiest families on board, organized a private dinner party in honor of Captain Edward J. Smith. Several distinguished guests, such as Archibald Butt, an advisor to President William Taft, attended.

A little before 9pm, Captain Smith was summoned and politely left for the bridge. Around 11:40 p.m. that night, the Titanic struck an iceberg.

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In an article dated 19 April 1912, the Washington Times reported the dramatic last minutes of the Wideners.

"Mrs. Widener did not want to go, and asked to be allowed to stand by her husband. However, Mr. Widener told her to save herself …. Mrs. Widener kissed her husband good-by," the Washington Times quoted a friend survivor.

To persuade his wife to board the lifeboat, George Dunton Widener "told her not to worry, as it was possible that all would be saved, and the danger did not seem great," the survivor recalled.

Harry helped his mother into lifeboat 4 and stood back with his father to await his fate.

The boat rowed away with Eleanor, her maid and 34 other people (all women and children).

George and Harry's bodies, if recovered, were not identified.

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Three years after the Titanic tragedy, which sank on 15 April 1912 claiming 1,517 lives, Eleanor Widener built the Harry Elkins Widener Memorial Library at Harvard University.

The library, which originally housed her son’s collection of about 3,300 precious volumes, is now home to 3 million volumes. It features one of the few remaining perfect copies of the Gutenberg Bible, donated by Harry’s brother and sister in 1944.

At the grand opening of the library on Commencement Day, June 24, 1915, Eleanor met Dr. Alexander Rice, a physician and explorer who received an honorary degree that day.

Within a few months, they were married.

According to newspaper reports, the bride, "noted for her beauty," wore a string of pearls which she saved from the Titanic disaster.

"She is said to possess one of the finest collections of jewels in the world. One string of pearls which Mr. Widener gave her for Christmas in 1909 was said to have cost $750,000," the New York Times reported.

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With Rice, Eleanor went on several dangerous expeditions in South American jungles. The couple explored over 500,000 square miles of the Amazon Basin, and are noted for being the first to use aerial photography and shortwave radio for mapping.

Eleanor died of a stroke while shopping in a Paris department store on July 13th, 1937.

Although the stolen necklace wasn't the most precious piece in her costly jewelry box, it was valued at about 14,000 Euro ($19,000).

"Perhaps even more, if it were sold at an auction," Tivoli spokesman Torben Plank Said. "However, it will not be possible to sell the necklace as it is known internationally."

A reward of 1,000 Euro (about $1,350) has been offered to the person who can lead to retrieving the necklace.