They say diamonds are a girl's best friend - the exception, of course, being if they're cursed. All gemstones have a story, and for some, those tales are filled with mystery, intrigue and even misfortune for their owners. From thefts to inexplicable deaths, these diamonds are believed to cause calamity, leaving many to wonder if their dazzle is worth the destruction.

Here are some of the most notorious stones in history, and the myths surrounding their supposed curse.

The Hope Diamond

The Cursed Hope DiamondThe Hope Diamond
Image via GIA

There are many reasons why the Hope Diamond is so well known throughout the world - including its stunning beauty, rare color, royal ties and impressive size. Adding to its intrigue is the fact that this awe-inspiring stone is also thought to have carried a curse.

Parade magazine noted that the book "The Smithsonian's History of America in 101 Objects" revealed how these rumors have accumulated over the decades.

In fact, some parties warned the Smithsonian Museum against accepting the Hope when Harry Winston decided to donate it, worrying that under America's ownership, it might doom the entire country to ill fate. Some even wrote to President Eisenhower, urging him to have the Smithsonian refuse the stone.

So where did this theory about its curse begin? Gemstone Advisor explained that according to one legend, Marie Antoinette was wearing the Hope when she was executed. Years later, the fancy dark grayish blue diamond was purchased by the collector Philip Henry Hope, but when his family went broke, his great grand nephew sold it in 1901.

After changing hands a number of times, it was bought by Evalyn Walsh McLean - a wealthy woman with a troubled family history. Her son died in a car accident at just nine years old, and furthermore, her daughter committed suicide when she was 25. Not only that, but her husband was committed to an insane asylum through the end of his life. Though Walsh apparently never thought there was a link between the diamond and these unfortunate events, many others disagreed.

In 1949, the 45.52-carat Hope Diamond was sold to Harry Winston - and today, it can be found in the Smithsonian Institute.

Gemstone Advisor noted that the Hope's cursed history has likely been exaggerated, but nonetheless, it continues to be a fascinating source of discourse for diamond enthusiasts.

The Black Orlov

Contrary to what one may assume from the name, this stone is not jet black in color, but more of a deep gunmetal. LiveScience explained that the cushion-cut diamond, which weighs a whopping 67.50 carats, was discovered in the early 1800s somewhere in India.

Like many other supposedly cursed gems, the Black Orlov's legend begins when it was reportedly stolen from the eye of a statue of Brahma, a Hindu god, at a sacred shrine. At the time, it weighed a jaw-dropping 195 carats.

Years later, the dark gray diamond was repossessed by Nadezhda Orlov, better known as Nadia Orlov, a Russian princess. Though the story has not been proven with hard evidence, LiveScience noted that the princess is believed to have jumped off a building to her death along with two of the diamond's other owners, shortly after acquiring the stone.

According to i09, the Black Orlov was eventually divided into three separate jewels in hopes of ending the curse. The source noted that Felicity Huffman was supposed to wear a necklace with one of the diamonds in it for the 2006 Oscars, but interestingly, changed her mind.

The Shah Diamond

Despite the fact that this lasque-cut diamond is not regarded for a particularly remarkable appearance, the dark history surrounding the Shah is what makes it so special. Gemstone Advisor reported that the stone, which has a rougher look than most well-known diamonds, has changed hands by a slew of rulers - and in fact, the names of three different Shahs are engraved in it. The final owner used the diamond as blood money to the Soviet Union in 1829 after a Russian diplomat was killed - and it is still owned by the country. Seeing as nearly every one of its owners has seen a gruesome end or ended up in dire political straits, it's unsurprising that the Shah Diamond is considered cursed.

The Koh-i-Noor

Now, this massive diamond, which weighs 186 1/16 carats, can be viewed in the Crown Jewels on display in the Tower of London. However, there is a rich history behind the Koh-i-Noor that only enhances its allure. As i09 reported, legend has it that every man who has ever worn this stone has lost his throne - which would explain why it was since only worn by women, including Queen Alexandra of Denmark, Queen Mary of Teck and the late Queen Elizabeth.

LiveScience explained that according to Babur's writings, the Persians stole the Koh-i-Noor from the Rajah of Malwa in 1306. The diamond then passed through many Hindu, Persian, Mongolian, Afghan and Sikh rulers' collections. The brutal battles that were fought to own this stone never seemed to cease. The news source even revealed that a Hindu description of the gem apparently states:

"He who owns this diamond will own the world, but will also know all its misfortunes. Only God or woman can wear it with impunity."

While it has resided in London for quite some time, the fight for the Koh-i-Noor isn't necessarily over. LiveScience revealed that India has still continued its attempts to reacquire it.

The Blue Diamond

As far as mysterious gems go, The Blue Diamond may be one of the most bizarre. In fact, LiveScience reported that its current whereabouts are unknown - but regardless of the fact that some have even questioned its enigmatic existence, it continues to cause some upset.

According to the legend, one of the Saudi royal family's janitors took a number of jewels from the Prince Faisal bin Fahd's bedroom in 1989. He supposedly concealed them in a vacuum cleaner bag and took them with him to Thailand. However, the authorities who have been questioned insist that there is no proof this stone is real. Eventually, the Thai police nabbed the thief, but he had already pawned off some of the jewels. When the pieces were returned, the royal family claimed that the Blue Diamond was not there.

The story gets stranger. A multitude of businessmen and diplomats that were said to be investigating the robbery either disappeared or were killed. Chalor Kerdthes, the officer in charge of the initial investigation, ordered the execution of the Thai jeweler who was thought to make the imitation jewels for the royal family. He, in turn, was sentenced to death in 1995.

Considering all of the deaths that are linked The Blue Diamond, it's no surprise that it's believed to cast a curse on anyone who possesses it by illegal means.