 The Titanic necklace, also known as the Heart of the Ocean, is a fictional blue sapphire necklace that was featured in James Cameron's 1997 movie "Titanic."  The necklace played a significant role in the movie's plot, as it was believed to have belonged to Louis XVI and was later worn by the character Rose, played by Kate Winslet.  While the necklace in the movie was fictional, it was inspired by real- life sapphire necklaces that were popular during the early 20th century. Sapphire jewelry was highly sought after during this time, as the gemstone was associated with wealth, royalty, and prestige.