Red diamond

Source: Wikipedia, the free encyclopedia.
This article is about the variety of diamond. For the coffee, see Red Diamond. For the comic book, see The Red Diamond.
Red diamond
Transparent to subtransparent to translucent
Density3.5–3.53 g/cm3
Polish lusterAdamantine
Optical propertiesIsotropic
Refractive index2.418 (at 500 nm)
BirefringenceNone
PleochroismNone
Dispersion0.044
Melting pointPressure dependent
References[1]

A red diamond is a

Moussaieff Red Diamond, which has internally flawless clarity.[5]

Origin of the red color

Despite decades of research, scientists are still inconclusive to the source of red color in diamonds. It is believed that the cause of the pink color in pink diamonds is the origin of red color as well but in a more concentrated dose. The most accepted theory is during the diamond's formation, plastic deformation is caused in the crystal lattice structure. Some of the atoms are misplaced as the diamond moves up through its kimberlite deposit, and the intense pressure of this movement causes the varying shades of pinks, or reds, to appear.[6] This lends credence to the hypothesis that red diamonds are dark pink diamonds, and why only one color intensity is possible. Red diamonds can be modified by the same secondary colors that can be found in pink diamonds as well.[7] The red color can also be produced by irradiating a colorless diamond with high-energy particles and then annealing it at high pressures and high temperatures.[8]

Properties determining value

Since red diamonds are classified as diamonds in every sense, they are also graded by the typical four Cs of Connoisseurship: Color, Clarity, Cut and Carat weight. Like with all fancy color diamonds, the Color attribute is considered the absolute most important characteristic of the diamond and is largely what determines its value. The next most important attribute is the diamond's carat weight, followed by its clarity, and cut.[6] Given their rarity, red diamonds are among the most expensive gemstones on average. Red diamonds can cost at least US$1 million per carat, and most of the known specimens are less than half a carat.[2]

Color

The color in red diamonds is assessed according to its

black diamonds, white diamonds, and red diamonds. Since the source of the red in red diamonds is considered to be a hyper-concentrated occurrence of pink, this would actually make red the darkest shade of pink possible, which is why it is only able to appear in one intensity. Red diamonds will only be graded Fancy Red, Fancy Brownish Red, Fancy Purplish Red, or Fancy Orangey Red. An easy way identify whether a red diamond is a counterfeit is if the seller is offering it with an intensity grade like other diamond colors (Fancy Light, Fancy Intense, Fancy Vivid etc.).[10] There are so few red diamonds that the GIA records show that over a 30-year period from 1957–1987, not a single GIA lab report with the term “red” was issued.[11] Some diamond polishers have achieved a GIA grading of Fancy Red for a diamond by re-polishing a Fancy Deep Pink diamond, although this is very hard to accomplish and has only been successfully completed less than a handful of times.[12]

Clarity

In order to determine the clarity of a diamond, it is examined under a

Moussaieff Red, was graded with an Internally Flawless clarity.[13]
A red diamond's clarity has little effect on its value because of the rarity of the color. A red diamond buyer will be far more interested in the purity of the red and the carat size in order to decide on its desirability. This is not true for all diamond colors, but it is especially so for the colors that are highest in demand, namely red, pink and blue. For the less expensive colors, such as yellow and brown, clarity will be more of a factor.[14]

Carat weight

Red diamonds are known for their small sizes. The majority of red diamonds on the market are less than 1 carat in weight. Only 5 red diamonds are known to exceed 5 carats in weight, the largest being 5.11 carats. Only a handful of red diamonds are discovered on an annual basis throughout the world, and most of them do not exceed 1 carat. Red diamonds are priced per carat, as all diamonds, and their per carat price is 300–400% higher than the per carat prices of the next most expensive diamonds, pink diamonds and blue diamonds.[15]

Fluorescence

Most red diamonds display fluorescence when placed under UV light. In the case of colorless diamonds, the presence of fluorescence is generally considered to lower a diamond's value. This is in fact completely arbitrary, as the blue glow may or may not appeal to a buyer, but it certainly has no bearing on the composition, durability or beauty of a diamond. However, it is a generally accepted notion in the diamond assessment world that the presence of fluorescence will lower a diamond's value. Just like with clarity, in the case of fancy color diamonds, this is not a detracting characteristic if it is present. If anything, its presence ensures the buyer that the diamond is genuine, as fluorescence is not recreated in lab grown diamonds. If a red diamond has fluorescence, it will not add or detract from its value or resale value in any way.[10]

Red diamonds as investment

Owing to their 6 to 7 figure price range, red diamonds are generally purchased by diamond investors or collectors, for the purposes of resale at a later date or to complete a diamond collection, according to the Diamond Investment & Intelligence Center.[16] Both investors and collectors only choose natural red diamonds for this purpose, as synthetic or color treated diamonds are essentially valueless. Often, when a buyer is seriously interested in the purchase of a very expensive diamond, they will ask for the diamond to be examined by the Gemological Institute of America (GIA) to ascertain that it is genuine. Of all the diamonds, red diamonds are the only ones whose size of under 1 carat will not disqualify them from being an investment stone, since so few red diamonds larger than that can be found in the market. Red is not a commonly synthesized diamond color, as it does not usually appeal to the general mass of diamond consumers.[17]

Red diamond source mines

The majority of red diamonds that are mined each year come from the

Moussaieff Red and the Kazanjian Red Diamond are known to have originated in Brazil and South Africa, respectively.[20][21] Generally speaking, red diamonds are found in the same locations where pink diamonds have also been discovered, and are not found if there are no pink diamonds nearby. Since the majority of the world's pink diamonds are discovered in the Argyle Mine, it follows that the majority of red diamonds are discovered there as well, although this is not exclusively the case. However, if a red diamond is traced to the Argyle mine in origin, it lends additional value to the diamond's price as is the case with all Argyle diamonds.[22]

Notable red diamonds

Red Diamond Weight
(carat) 		Notability
Moussaieff Red Diamond 5.11 Largest red diamond in the world, discovered in the 1990s by a Brazilian farmer in the Abaetezinho River [23]
Kazanjian Red Diamond 5.05 Second largest red diamond in the world
DeYoung Red Diamond 5.03 Acquired at an estate sale by Sydney de Young where it was sold as a garnet hat pin [24]
Graff Purplish-Red Diamond 2.26 A modified octagonal-cut mounted in a pink-gold ring. Sold for $2.65 million at auction in 2007.[25]
Argyle Everglow 2.11 Graded as fancy red, mined from Argyle diamond mine.[26]
Argyle Enigma 1.75 Fancy red radiant cut diamond from Argyle diamond mine, sold at Argyle's 2019 tender.[27]
Hancock Red 0.95 Mined in Brazil. Purchased by Montana rancher Warren Hancock in the 1950s and sold for a 6500% profit in 1987. [28][25]
Rob Red 0.59 The purest red diamond measured visually and instrumentally to date in the world.[25]

See also

References

  1. ^ "Diamond". WebMineral. Retrieved July 7, 2009.
  2. ^ a b Trevor Nace (2 November 2015). "12 Most Expensive Gemstones In The World". Forbes. Retrieved 21 May 2019.
  3. ^ "Colour in Diamonds". Natural History Museum of L.A. Minblog. January 21, 2013.
  4. ISBN 978-1-4022-0409-8
    .
  5. ^ "The Splendor of Diamonds: The Moussaieff Red". Smithsonian Institution. Retrieved 26 March 2017.
  6. ^ a b Rachminov, E. (2009). The Fancy Color Diamond Book: Facts and Secrets of Trading in Rarities. New York: Diamond Odyssey.
    ISBN 978-9659149902
    .
  7. ^ a b Grading Fancy-Color Diamonds Archived 2014-11-02 at the Wayback Machine. Gemological Institute of America
  8. ^ Meili Wang, Guanghai Shi, and Joe C.C. Yuan (2017). "Mixed-type treated red HPHT synthetic diamond". Gems & Gemology. 53 (1): 139–140.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  9. ^ "What Are The Colors Of Fancy Diamonds?". investments.diamonds. Diamond Investment & Intelligence Center. 16 June 2016. Retrieved 25 March 2017.
  10. ^ a b "Fancy Red Diamonds: The Guide For Buyers and Investors". diamondenvy.com. Diamond Envy. Retrieved 27 March 2017.
  11. ^ "Red Diamonds – The Rarest of them All". GIA.edu. Gemological Institute of America. 28 May 2014. Retrieved 26 March 2017.
  12. ^ "The Kimberley Red diamond has been recut". Diamond World. Retrieved 26 March 2017.
  13. ^ Sebastian Naturski. "Diamond Color". Your Diamond Teacher. Retrieved 26 March 2017.
  14. ^ "Characterization And Grading Of Natural-Color Pink Diamonds". GIA.edu. Gemological Institute of America. Retrieved 25 March 2017.
  15. ^ "How Are Colored Diamonds Formed?". Diamond Price Guru. Retrieved 25 January 2017.
  16. ^ "Fancy Color Diamonds Investment Guide – Part 1". investments.diamonds. Diamond Investment & Intelligence Center. 4 May 2016. Retrieved 27 March 2017.
  17. ^ "What is Chemical Vapor Deposition?". Innovateus. Retrieved 26 January 2017.
  18. ^ "The Famed Argyle Diamond Mine – A Source of Sparkle". Naturally Colored. Retrieved 27 March 2017.
  19. ^ "The World's Rarest Gemstone". Gem Select. Retrieved 26 March 2017.
  20. ^ "Kanzanjian Red Diamond". American Museum of Natural History. Retrieved 26 March 2017.
  21. ^ "Diamond Mining in Minas Gerais, Brazil". GIA. Retrieved 26 January 2017.
  22. ^ "Exceptional Pink to Red Diamonds: A Celebration of the 30th Argyle Diamond Tender". GIA. Retrieved 26 January 2017.
  23. ^ "A Man of Good Fortune". Haaretz. 10 October 2001. Retrieved 29 April 2012.
  24. ^ "DeYoung Red Diamond". Internet Stones.com Network. Retrieved 26 March 2017.
  25. ^ a b c The World’s Most Famous Red Diamonds, Rayah Levy, FCD Invest, May 7, 2021
  26. ^ Argyle Everglow : One of the world's rarest Red Diamonds unveiled in New York
  27. ^ Rare Argyle diamonds attract bidding bonanza as closure nears, Australian Mining, November 22, 2019
  28. ^ "10 jewels that made history". Christies.

Further reading

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