Experts in the United States have used computer models to show that the 45.52 carat diamond, once owned by King George IV, was cut from a larger diamond that had been in the possession of the French authorities and was known as the French Blue.
"The evidence very much supports the theory that it was cut from the French Blue diamond," said Jeffrey Post, the curator of gems and minerals at the National Museum of Natural History in Washington, part of the Smithsonian Institution.
The history of the Hope diamond, believed to be the world's largest deep blue diamond, is full of twists.
The 112-carat stone that became the Hope was purchased by Jean Baptiste Tavernier, a merchant, in the 17th century, probably from the Kollur mine in Golconda, India. This stone was sold to King Louis XIV of France in 1668. In 1673 it was recut by the court jeweller, resulting in a 67-carat stone. It was said to be steely blue and in inventories it was known as the Blue Diamond of the Crown, or French Blue.
In 1749 the stone was reset and in 1791, at the height of revolutionary fervour, the jewels of the French Royal Treasury were seized - during looting in 1792 the French Blue was stolen. It reappeared in 1812 when a deep blue diamond of more than 44 carats was said to have been in the possession of Daniel Eliason, a London diamond merchant. Several references suggest it was acquired by George IV and sold on his death in 1830. It then made its way into the collection of Henry Philip Hope, from whom the diamond takes its name. It was always suspected that stone had been cut from the French gem.
In 1910 the Hope was bought by the mining heiress Evalyn Walsh McLean, of Washington. On her death it was bought by Harry Winston Inc and later donated to the Smithsonian Institution.
The findings from new research into the diamond, broadcast last night in the US on the Discovery Channel, involved documents, drawings and statistics of the three stones - the Tavernier stone, the French Blue and the Hope - to create computer models. The two smaller "versions" were able to fit back into the Tavernier stone. "They fit inside one another very well. It all makes very good sense," Mr Post told The Washington Post.
Legend says the diamond is cursed because Mr Tavernier did not buy the stone but stole it from the eye of a statue of the Hindu goddess Sita. The merchant was later torn apart by wild dogs in Russia. Next to suffer from the curse were Marie Antoinette and Louis XVI, who were beheaded.
The curse also affected the Hope family, who went bankrupt. Mrs McLean too suffered no small amount of misfortune: her first son died in a car crash, her daughter killed herself and her husband was declared insane. By contrast, the stone's ownership by the Smithsonian has been much more fortunate. Today it is the institution's most popular artefact.