Red diamond

Red diamond
Red diamond
	DeYoung Red Diamond
General
Category	Native minerals
Formula ; (repeating unit)	C
Strunz classification	1.CB.10a
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) ; H-M symbol: (4/m 3 2/m)
Identification
Formula mass	12.01 g/mol
Color	Red
Crystal habit	Octahedral
Twinning	Spinel law common (yielding "macle")
Cleavage	111 (perfect in four directions)
Fracture	Conchoidal (shell-like)
Mohs scale hardness	10 (defining mineral)
Luster	Adamantine
Diaphaneity	Transparent to subtransparent to translucent
Density	3.5–3.53 g/cm3
Polish luster	Adamantine
Optical properties	Isotropic
Refractive index	2.418 (at 500 nm)
Birefringence	None
Pleochroism	None
Dispersion	0.044
Melting point	Pressure dependent
References

Last updated February 23, 2024

A red diamond is a diamond which displays red color and exhibits the same mineral properties as colorless diamonds. Red diamonds are commonly known as the most expensive and the rarest diamond color in the world, even more so than pink or blue diamonds, as very few red diamonds have been found.^[2] Red diamonds, just like pink diamonds, are greatly debated as to the source of their color, but the gemological community most commonly attributes both colors to gliding atoms in the diamond's structure as it undergoes enormous pressure during its formation.^[3] Red diamonds are among the 12 colors of fancy color diamonds, and have the most expensive price per carat. They will typically run in the hundreds of thousands of dollars per carat range.^[4] Since they are the rarest color, it is difficult to find them in large sizes, and they are mostly found in sizes less than 1 carat. Red diamonds only exist with one color intensity, Fancy, although their clarities can range from Flawless to Included, just like white diamonds. The largest and most flawless red diamond is the 5.11 carat Fancy Red 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 hue and saturation.^[7] Red diamonds can occur with secondary colors, such as brown-red, orange-red, or purple-red, but red is not a modifying color for any other diamond color. Additionally, red diamonds never appear with a tertiary modifying color, as is the case in other diamond colors.^[9] A pure red diamond is ideal but an even rarer find than a red with a secondary color. Like with other diamond colors, a purely red diamond will fetch a higher per carat price than one with a secondary hue. Brownish red and Orangey red diamonds are generally considered inferior to Purplish Red diamonds and are priced accordingly. All of these colors run upwards of $400,000 per carat, but a pure red diamond can cost significantly more per carat. Few colors of fancy color diamonds are characterized by having a singular color intensity. This phenomenon only exists with three colors: 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 loupe, which is magnification device that enlarges the visual field 10X. Diamonds are inspected to determine whether there are inclusions on its outside or on the inside. Red diamond clarity is measured like all diamonds on the scale from Flawless to Included. Most red diamonds fall within the range of VS1 – SI2 due to the nature of how they were formed. However, the largest and most famous red diamond, the 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 Argyle diamond mine in Kimberley, Western Australia.^[18] However, they have also been discovered in Brazil, Russia, and certain African countries. The first red diamond known to public record was acquired in 1956 by a Montana rancher named Warren Hancock, who later sold it for a record setting $927,000 at auction in 1987.^[19] Other diamonds of note, such as 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]

Related Research Articles

A gemstone is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments. However, certain rocks and occasionally organic materials that are not minerals are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones.

Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al₂O₃) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived via the Latin sapphirus from the Greek sappheiros (σάπφειρος), which referred to lapis lazuli. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs. Sapphire is the birthstone for September and the gem of the 45th anniversary. A sapphire jubilee occurs after 65 years.

<span class="mw-page-title-main">Ruby</span> Variety of corundum, mineral, gemstone

A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum. Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.

The Argyle Diamond Mine was a diamond mine located in the East Kimberley region in the remote north of Western Australia. Argyle was at times the largest diamond producer in the world by volume, although the proportion of gem-quality diamonds was low. It was the only known significant source of pink and red diamonds, and additionally provided a large proportion of other naturally coloured diamonds, including champagne, cognac and rare blue diamonds.

Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects, called blemishes. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut.

A chemically pure and structurally perfect diamond is perfectly transparent with no hue, or color. However, in reality almost no gem-sized natural diamonds are absolutely perfect. The color of a diamond may be affected by chemical impurities and/or structural defects in the crystal lattice. Depending on the hue and intensity of a diamond's coloration, a diamond's color can either detract from or enhance its value. For example, most white diamonds are discounted in price when more yellow hue is detectable, while intense pink diamonds or blue diamonds can be dramatically more valuable. Of all colored diamonds, red diamonds are the rarest. The Aurora Pyramid of Hope displays a spectacular array of naturally colored diamonds, including red diamonds.

The Gemological Institute of America (GIA) is a nonprofit institute based in Carlsbad, California. It is dedicated to research and education in the field of gemology and the jewelry arts. Founded in 1931, GIA's mission is to protect buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality. The institute does so through research, gem identification and diamond grading services and a variety of educational programs. Through its library and subject experts, GIA acts as a resource of gem and jewelry information for the trade, the public and media outlets.

The Moussaieff Red Diamond is a diamond measuring 5.11 carats with a triangular brilliant cut, rated in color as Fancy Red by the Gemological Institute of America. It is the world's largest known red diamond, the rarest of all diamond colors.

The Ocean Dream is a diamond measuring 5.51 carats, rated in color as Fancy Deep Blue-Green by the Gemological Institute of America. The Ocean Dream is the first and one of the only natural diamonds known to the GIA to possess a blue-green hue, making it one of the rarest diamonds in the world. (A blue-green colour is commonly seen in artificially enhanced diamonds, whose colour is imparted by various irradiation methods. The Ocean Dream originated in Central Africa, and is currently owned by the Cora Diamond Corporation.

The Pink Star, formerly known as the Steinmetz Pink, is a diamond weighing 59.60 carats, rated in color as Fancy Vivid Pink by the Gemological Institute of America. The Pink Star was mined by De Beers in 1999 in South Africa, and weighed 132.5 carats in the rough. The Pink Star is the largest known diamond having been rated Vivid Pink. As a result of this exceptional rarity, the Beny Steinmetz Group called Steinmetz Diamonds took a cautious 20 months to cut the Pink. It was unveiled in Monaco on 29 May 2003 in a public ceremony.

The Pumpkin Diamond is a diamond weighing 5.54 carats rated in color as Fancy Vivid Orange by the Gemological Institute of America. While this may seem small when compared to other famous diamonds, the Pumpkin Diamond is, in fact, one of the largest Fancy Vivid Oranges the GIA reports having rated and is unique compared to other orange diamonds because it is light-colored and notably intense. The Pumpkin Diamond was mined in Central African Republic and then imported into South Africa for sale, it was later cut and polished by William Goldberg, and put to auction at Sotheby's where it was bought by Ronald Winston of the House of Harry Winston for the price of $1.3 million. It is currently estimated to be valued at $3 million.

<span class="mw-page-title-main">Diamonds as an investment</span>

Diamonds were largely inaccessible to investors until the recent advent of regulated commodities, due to a lack of price discovery and transparency. The characteristics of individual diamonds, especially the carat weight, color and clarity, have significant impact on values, but transactions were always private. With the standardized commodity as an underlying asset, several market traded financial instruments have been announced.

<span class="mw-page-title-main">Diamond (gemstone)</span> Gemstone

Diamond is one of the best-known and most sought-after gemstones. They have been used as decorative items since ancient times.

Graff is a British multinational jeweller based in London. It was founded by British jeweller Laurence Graff in 1960. A vertically integrated company, Graff operations comprise the design, manufacture and retail distribution of jewellery and watches.

The Archduke Joseph is a colorless, antique cushion-shaped brilliant, originally weighing 78.54 carat, purchased by Molina Jewelers of Arizona sometime in the late-1990s and slightly re-cut to 76.45 carat to improve clarity and symmetry. It is, on the Gemological Institute of America (GIA) color and clarity scales, a D grade, IF diamond and the largest DIF ever graded at the GIA; and it is of type IIa.

The Princie Diamond is an approximately 34.65 carat cushion-cut fancy intense pink diamond discovered 300 years ago in the Golconda mines. Christie's say that the Princie Diamond is believed to be the fourth largest pink diamond in the world, after the Daria-i-Noor, the Noor-ol-Ain - which are both part of the Iranian Crown Jewels; both were cut, according to experts, from one single c. 242 carat pink diamond, - and the Pink Star, a diamond weighing 59.60 carats.

<span class="mw-page-title-main">Ocean Paradise Diamond</span>

The Ocean Paradise is a diamond measuring 1.6 carats after polish and was discovered in Brazil and currently owned by the Nahshonov Group. When discovered, it measured 6.43 carats. The Ocean Paradise is the second and one of the only natural diamonds known to the GIA to possess a blue-green hue, making it one of the rarest diamonds in the world.

The Winston Blue is the name given to what was the largest flawless vivid blue diamond bought by Harry Winston, Inc. on May 15, 2014, from an anonymous person for $23.8 million at Christie's Geneva Magnificent Jewels sale. The approximately $1.8003 million per carat price paid for the 13.22-carat diamond is a world record for a blue diamond. Harry Winston, Inc. had also bought a 101.73-carat colorless diamond named Winston Legacy at Christie's Geneva jewelry auction in 2013. The American luxury jeweler had then paid $26.7 million for the colorless diamond, which is a world record for the highest price paid per carat for a colorless diamond.

<span class="mw-page-title-main">Blue diamond</span> Blue-colored variant of a diamond

Blue diamond is a type of diamond which exhibits all of the same inherent properties of the mineral except with the additional element of blue color in the stone. They are colored blue by trace amounts of boron that contaminate the crystalline lattice structure. Blue diamonds belong to a subcategory of diamonds called fancy color diamonds, the generic name for diamonds that exhibit intense color.

Pink diamond is a type of diamond that has pink color. The source of their pink color is greatly debated in the gemological world but it is most commonly attributed to plastic deformation that these diamonds undergo during their formation.

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