The diamond that is said to be cursed is the Hope Diamond.
The Hope Diamond is the world's most famous diamond that is said to be cursed as legend claims that the Hope Diamond, which is a 45.52 carat deep blue gem brings murder, financial ruin and tragedy to anyone that owns or wears it.
Other historically significant diamonds that are also rumored famously to carry a curse include:
The Moon of Baroda, which is a 24-carat canary-yellow diamond that is famous for being worn by Marilyn Monroe in the film Gentlemen Prefer Blondes.
Legend dictates that the diamond brings terrible bad luck to its owner if it crosses an ocean.
The Sancy Diamond is a 55.2-carat yellow diamond whose royal owners faced horrific deaths—including beheadings and assassinations—and which was also famously swallowed by its own courier to avoid being stolen.
The Koh-I-Noor is a 105-carat diamond deeply tied to the history of Indian, Persian, and British rulers.
The legend states the curse only affects male owners, claiming that any man who wears it will meet a tragic end.
The Black Orlov is a 67.50-carat cushion-cut stone rumored to be stolen from a Hindu statue.
The Black Orlov is infamous for supposedly driving three of its owners—including a pair of Russian princesses—to suicide by jumping from tall buildings.
A poor man's diamond is the colloquial nickname that refers to several different gemstones, which resemble diamonds or cost much less than real diamonds, while offering a similar and brilliant aesthetic.
The phrase "poor man's diamond" refers to gemstones which include.
Aquamarine, which is a pale blue, March birthstone and is a durable, semi-precious beryl crystal that provides a clear and icy look for a fraction of the cost of a traditional diamond.
Natural zircon, in gemology, is sometimes referred to by the nickname "a poor man's diamond" because it's high refractive index creates intense fire and sparkle, which makes it one of the oldest natural diamond simulants.
Herkimer Diamonds, which are exceptionally clear, double terminated quartz crystals found primarily in Herkimer County, New York.
Collectors of the Herkimer Diamond affectionally call them the poor man's diamond because they grow naturally with beautiful, raw diamond like facets.
And cubic zirconia, which is often just called a diamond simulant, CZ or cubic zirconia is regularly referred to as an affordable alternative for a "lookalike" diamond.
It's also visually convincing when new, although it also lacks the durability and scratch resistance of a true diamond.