Red Diamonds: What You Should Know

Diamonds come in all shapes and sizes, and their value is based on factors such as cut, clarity, rarity, and color. Red diamonds, in particular, are one of the rarest stones in the world — so rare that only 30 true gem-quality red diamonds are known to exist, with most of them being less than half a carat.

A red diamond displays a fiery color throughout its prism and exhibits all the same mineral properties as colorless diamonds. Red diamonds are also the rarest of colored diamonds, making them very difficult to find in large sizes. They only exist with one color intensity – Fancy – and, much like white diamonds, their clarities range from Flawless to Included.

What makes them red?

Colored diamonds, such as blue and pink diamonds, get their fancy color from chemical impurities such as nitrogen and boron. Red diamonds do not contain any impurities and are pure carbon. The red hue comes from its atomic structure, which has a rare deformation. Gemologists and diamond experts believe that the lattice defect causes the red color of the diamond, which shows stress lamination during its formation. When light passes through the deformed internal structure, the light bending results in the red color. Sometimes, red diamonds appear to show different colors because there are different amounts and sources of light passing through them. For one to fully appreciate the real beauty of a red diamond, it is advisable to view them under natural daylight, where they shine the best and the brightest.

The red diamond’s colorful history

Red diamonds are the rarest diamonds on earth, which is why when one weighing an incredible 5.11 carats was unearthed, it gained international attention. This famous red diamond — the largest in the world to date — is the Moussaieff Red Diamond which is also the largest fancy red stone ever graded by the Gemological Institute of America.

A farmer in Brazil found the deep red diamond in the mid-90s in the Abzetezinho River. In the rough, it weighed a total of 13.90 carats, and according to Internet Stones, the stone was most likely formed in the mining area’s alluvial deposits. The William Goldberg Diamond Corporation of New York, which is famous for possessing remarkable stones such as the Guinea Star and the Premier Rose, bought the red diamond to add to its impressive collection. The Goldberg Corporation then cut the stone into its distinct triangular brilliant cut (also known as a trillion or trilliant cut), which resulted to a stunning transformation — and a loss of over 8 carats in the process. Nonetheless, the red diamond retained all its breathtaking characteristics and was named the Red Shield. In the early 2000s, it was purchased by the Moussaieff Jewelers for around $8 million and was renamed the Moussaieff Red Diamond. Michael Hing, an expert gemologist who saw the diamond in person, said, “It’s a really surprising cranberry color, quite unlike any other diamond I’ve ever seen.”

The Moussaieff Red captured the attention of museums all over the world, and was in fact displayed twice at the Natural History Museum of the Smithsonian in Washington, DC. It was featured as part of the Splendor of Diamonds exhibit which ran from June 2 to September 30, 2003, along with other legendary gems such as the Millennium Star, the Pumpkin Diamond, the Heart of Eternity, and the Ocean Dream. It was later selected to be part of yet another exhibit which ran from July 2005 to February 2006, where it was displayed together with the Steinmetz Pink and the Aurora Collection.

Other notable red diamonds include The Hancock Red, which was purchased by Montana rancher Warren Hancock in the 1950s and sold for a whopping 6500% profit in 1987, as well as The Rob Red, the purest red diamond measured visually and instrumentally to date in the world. There are also stories about the second-largest red diamond in existence, the Kazanjian Red Diamond, which is said to be a 5.05-carat emerald cut-stone found in 1927 in South Africa and bought by an anonymous collector. Its whereabouts and name are unknown, making it one of the most mysterious diamonds ever.

The De Young Red is the next known largest red diamond weighing in at an impressive 5.03 carats. It features a brilliant round cut and a slight brownish tint, which is why it was initially sold as a garnet hat pin, acquired at an estate sale by Sydney de Young, a Boston jewelry seller. Among the most distinct characteristics of the De Young Red are its facets on the diamond’s crown, which resemble kites that are split in two, making it more brilliant than any other diamond with an ordinary round cut. De Young noted that the diamond possessed an unusually high quality for its age, so he had it tested at a laboratory, where it was discovered to be a red diamond. It was then given to the Smithsonian Institution’s National Gem and Mineral Collection after De Young’s death in 1986, as per his wishes. It is the only red diamond on public display.

Another notable red diamond is the Supreme Purple Star, which appears to have a deep purple color from one angle. When it is rotated in the light, it takes on a purplish red hue, hence the name.

Where to find red diamonds

A huge portion of red diamonds come from the Argyle Mine in Kimberley, Western Australia. They have also been discovered in Brazil, Russia, and Africa. Red diamonds are generally found in locations where pink diamonds have also been discovered. So far, red diamonds have not been found in areas with no pink diamonds nearby. Incidentally, most of the world’s pink diamonds are discovered in the Argyle Mine, so the majority of red diamonds are discovered there as well.

Visit the Biltmore Loan Jewelry website to learn more about red diamonds and other rare gemstones — especially if you’re selling them! For a free market appraisal, you may visit our locations or contact us at 480-991-5626 for Scottsdale and 480-705-5626 for Chandler.