The sapphire pendant which is believed to have inspired the love story in the film Titanic is to go on display in Belfast.
The sapphire pendant is going display
In the movie, actress Kate Winslet is presented with a necklace.
The real-life pendant was given by an English businessman to his lover.
He drowned, but the woman survived and passed the jewel on to her daughter.
The pendant, along with a purse and trunk keys, will now go on display aboard the Nomadic, the ship which ferried passengers out to the Titanic.
David Scott-Beddard of the Nomadic Trust said the artefacts would be kept in a secure cabinet but, from Monday, would be exhibited on the Nomadic which is berthed near Belfast's Odyssey complex.
The Titanic sank on its maiden voyage to New York
"The pendant that we have just acquired and is going to go on display on Nomadic, isn't actually the fictitious Heart of the Ocean from James Cameron's film," he said.
"This pendant is from the Titanic and was the inspiration for James Cameron to write the love story that he included in his film with Kate Winslet."
Mr Scott-Beddard described the pendant as being "quite small, only about an inch long," with an "oblong sapphire surrounded by diamonds and attached to a very simple thin chain".
"The true story is that a businessman from the English Midlands, who owned three or four confectionary stores, left his wife and children, for a young lady called Kate Florence Philips who worked in one of his stores."
He said the man drowned when the Titanic sank, but the woman survived, managing to hang on to the pendant, her purse and the keys to her trunk.
"She also found out four weeks later that she was pregnant," he said.
"A friend of mine has had the necklace for quite some time. He bought it from Kate Philips's daughter, a lady called Ellen Mary Walker, who lived in Worchester.
The Nomadic as she looked early in the 20th century
"She died last year and her ashes were scattered on the site of the wreck site of the Titanic."
He said a friend bought the necklace, purse and keys "quite a few years ago".
A pocket-watch recovered from the wreck of the Titanic was also bought by Mr Scott-Beddard and will go on display along with the other items.
"We are pretty sure that, because of the fictitious story and the fascination with Kate Winslet's Heart of the Ocean necklace, a lot of people will want to come and see the real necklace," he said.
Built in 1911, the Nomadic was bought by the government to be restored and taken from France to Belfast last July.
Thousands of people have visited the Nomadic since it was berthed beside the Odyssey at Easter.
It is hoped the vessel will become a major tourist attraction and be fully restored for its 100th anniversary in four years time.