Diamonds & Hearts

Ancient Diamonds

“Diamonds” (adámas, Greek) means “unalterable” are used for hardness in industry and solidarity in jewelry – 4C’s of carat, cut, color, and clarity are noted.  De Beers is credited with marketing engagement rings using diamonds in the mid-20th century.

Indian diamond trade from before 4BC extended until discovery in Borneo in 700 AD, Brazil in 1725, and South Africa in 1867 (becoming the largest diamond producer).  Presently, however, Surat, India, cuts and polishes over 90% of diamonds, with trading of over 85% rough diamonds (and 50% of cut, less for industrial) being done in Antwerp, Belgium with over 12,000 experts.  Interestingly, in this 21st century, “perfectly identical” diamonds to those mined can be produced synthetically.

The first diamond engagement ring was thought to be received by Mary of Burgundy in 1477 (from Maximilian I the Archduke of Austria).  The oldest diamond-related book, the “Diamond Sutra” was found in Chinese Mogao Caves in AD 868, denoting teachings of Buddha.

The birthstone of the April-born, a “diamond jubilee” indicates a 60-year anniversary.

“Blood diamonds” are used in politically taken-over diamond mines, financing wars.  Kimberley Process (2002) allowed conflict diamonds to be removed from diamond trading process, via certification, though about 2% still sneak in.

Annually, presently, about 6 tons (i.e. 30 million carats) for gemstones and over 100 million carats of industrial use are mined.

Current Diamonds: The (Ultimately Marketed) Present

Valuation of a diamond is based upon the Four “C”s – carats, cut, clarity, color, – are used to designate a diamond, with the first two being quantified, the latter two being judged subjectively to some extent.  Also, fluorescence, source, and which gemological institute evaluated, are also methods of valuation.  The two gemological associations are –

  • (1) Gemological Institute of America (GIA)
  • (2) Diamond High Council (HRD)

Recently, for-profit organizations in Antwerp & New York, for example, seek to accomplish similar certification for a lower price.

Carat

1 carat = 200mg; “1 point = 2mg” or 1/100 of a carat.

Though price per carat increases, it is not linear, but increases dramatically around “milestones” (e.g. 1 carat).  Martin Rapaport’s Diamond Report prices retail diamonds, with jewelers trading based upon discounts off it (e.g. “R-2%”).

“TCW” or total carat weight is used to denote the sum of all diamonds (or other stones) in piece(s) of jewelry.

Clarity

Clarity measures “inclusions” or internal defects,  with number, size, color, location, orientation, and visibility being noted.  Using upto 10x magnification, agencies such as GIA allow about 20% of the diamonds to be sufficiently “gemstone” grade – with 80% otherwise designated for industrial use.  Of these 20%, “eye clean” are as visibly accepted gemstones per the consumer’s eye.

Color

“D” is colorless, with “G”-“J” being near-colorless, “K”-“M” being slightly colored, “N”-“Y” being light yellow or brown, and “Z” being brightly yellow.  Such color changes of yellow usually occur with Nitrogen replacing a Carbon, and actually a “Z” or a other-colored diamond such as pale pink or blue may increase value markedly.

Cut

Mathematically-based guidelines (e.g. Tolkowsky, 1919-based round birllaint 57 facets or polished faces – 33 on crown (top half) and 24 on pavilion (lower half) with girdle in between).  The CROWN REFRACTS light and the PAVILION REFLECTS LIGHT.  Marcel Toklowsky made specific calculations for table percentage being 53%, depth percentage 59%, pavilion angle 41, crown angle 35, pavilion depth 43%, crown depth 16% (all estimated, for maximum light reflection).

Shape

Diamonds not cut into a “round brilliant” shape are cut into “fancy cuts” – baguette, princess, heart, briolette (form of a rose), pear cuts have been introduced, with newer “cushion, radiant (princess with rounded vs. square edges), and Asscher.  A princess cut accentuates “fire” rather than luster – wastes the LEAST crystal.

Quality

Cut algorithms which determine the quality of a diamond are now specified as “facetware” by the GIA.  A 0.99 carat stone will be a better buy (for not having achieved a “milestone” price), though compromising “cut” with its associated radiance at times being possible.

Brilliance (white light reflections from external and internal surfaces); Fire (spectral colors produced from white light dispersion); and Scintillation (small flashes of light seen when moving a light source with the diamond) are helpful in light quality evaluation.

Setting of the diamond – prong (4-6 claws cradling the diamond) vs. bezel (metal completely surrounding diamond) vs. channel (stones set adjacent, without metal) – helps improve light quality.
Fluorescence, or ability to glow in UV light, is present in about 1/3 of diamonds (about 1/3 of these being blue).

Cleaning a diamond can be done using steam, ammonia, or ultrasonic-based kits.

(Portions of this article and others related to this topic were obtained from information from various research sources, including: Wikipedia.org, articles such as diamondsnews.com, hwgem.com, diamondland.be, and others)

Diamonds of Tomorrow

Tomorrow’s diamonds can be synthetically produced by high temperature-pressure processes, simulating the earth’s magma-related volcanic cycle which results in diamonds’ natural formation.

Why are diamonds so precious? Those found at the earth’s surface are 1 billion to 3.3 billion years old, which is significant considering the earth’s age is little over 4 billion years… so a (natural) diamond is practically “forever” compared to human lives, and commitments such as marriages.

Meteorite impacts with resultant “stellar” diamonds have also been found.

The hardness of a diamond usually means only other diamonds can scratch them…

Most diamonds are electrical insulators, though some blue diamonds are electrical semi-conductors (originating from Boron); also, diamonds are lipophilic (stick to oil) and not water. Irradiation can give diamonds the color green also; and plstic deformation can cause pink or red diamonds; black or “Carbonado” diamonds are from inclusion of dark appearance. Hardness testing can also occur; a high conductive property also exists in diamonds.

Diamonds are cut in Surat, India; distributed and handled in Antwerp, and sold in New York City, New York.

DeBeers, which controlled 80% of the market (via mines) till the 21st century, now owns less than 50%, with Russian companies such as Alrosa, BHP Billiton (the world’s largest mining company), Rio Tinto, Diavik, and Murowa being others, as well as Petra Diamonds.

Flaws (inclusions) can be cut out of a diamond in the discarded part – “chiseling” a diamond or cutting using a diamond saw are options. Repolishing, crack-filling, and other techniques are used to treat problems within a diamond.

  1. W Ayer & Son in the mid 1950’s revived the diamond engagement ring as “being forever” for DeBeers. Australia’s Argyle diamond mine (1986) introduced the “brown diamond” as a gemstone instead of being relegated to industry (as 80% of the mined diamonds are otherwise relegated).

Electrical applications of diamonds (e.g. superconductor, heat sink, etc.) may exist.

Synthetic Diamonds

High-pressure & temperature-formed

Nitrogen impurities give synthetic diamonds which are HPHT-formed (high-pressure, high-temperature), and color can be changed (as previously discussed) using boron or irradiation.

Chemical vapor deposition can also create diamonds – often used for coatings, but can form crystals (low pressure). Annual production of maybe 60,000 natural to 1 synthetic diamonds by carats occurs presently – though for unusual colors, they are more likely to be synthetic gems.

“Similants” which are non-diamonds but appear to be diamonds include cubic zirconia or Moissanite (silicon carbide). True diamonds can be “treated to change color, fill cracks, and/or remove inclusions by drilling…”

Telling fit from counterfeit diamonds

Instead of the abrasive scratch test (where a diamond can scratch another diamond), the diamond’s conductivity is instead tested to help determine whether it is genuine. By its conduction, a diamond causes a rapid drop in a heated copper probe’s tip. Interestingly, silicon carbide as a simulant can have good conduction as well, mimicking that quality of diamonds – in such cases, detailed optical analysis can help, as can spectroscopy, UV-light-proved luminescence, and other techniques.

CVD diamonds have orange fluorescence, synthetic diamonds don’t have the inclusions to extent that natural diamonds would and hence other such characteristics are found.

Overall, in theory, the choice may end up being between a 4 billion-year vs. a few days-old diamond – although very difficulty to tell to the layperson’s naked eye, it is very possible that the person receiving the engagement ring may be more disappointed to have the latter than the former. Unlike most things in life, diamonds get better with age. 

(Portions of this article and others related to this topic were obtained from information from various research sources, including: Wikipedia.org, articles such as diamondsnews.com, hwgem.com, diamondland.be, and others)

[A uniquely created diamond for Tiffany’s (diamondland.be)]

Ravish Patwardhan, MD