Talk:Diamond color

More Color Info?

The article does not mention what specifically leads to pink, purple or black diamonds. Does anybody know what causes this? Are, or how are black diamonds rated; by opacity?

Generally impurities cause diamond colors; blue=boron, yellow=nitrogen. The source of pink is unknown (2014)--N7bsn (talk) 18:05, 24 December 2014 (UTC)

Expand
Shouldn't this article be expanded to discuss the grading of fancy-colored diamonds? All it currently (10/18/06) says about fancy-colored diamonds is that they are graded on a different scale than regular diamonds. ~ ONUnicorn (Talk / Contribs) 14:43, 18 October 2006 (UTC)

To answer the above question to the best of my ability... Fancy colored diamonds are not graded in a best to worst scale the same way as white diamonds. The "color grades" given to fancy colored diamonds are more descriptive phrase than definitive grade. Combinations of descriptive words such as Fancy, Intense, Vivid, Light, Deep and Dark are attached to the colors of the stones.

Black Diamonds are opaque black stones. They are simply heated until done. No in between shades that I have ever seen.

The valuation of diamonds on a wholesale level is based on simple supply and demand factors. There are several independent sources that track the sales of diamonds being traded at this level. The data that is collected is then averaged and compiled into a grid which is then used as the base price for an average stone.

Due to the rarity of Natural Fancy Color Diamonds, and the closed doors behind which they are sold, there is not enough sales data to distill down into definitive price classes for fancy colored diamonds. It is more of case of what the market will bear at any given time.

Hope that helps someone, 70.20.66.113 01:09, 28 January 2007 (UTC)

Summary table of grading scales
I just finished a grading summary table of various grading systems. I would like to know if it shows on various screens well. Please drop a note here if you notice problems, and if severe please remove the transclusion - If you do so, please specify here what the problem was. The table is very complex, and while you might take a shot at fixing any errors, please be aware that small changes can screw up the formatting.

I would like to confirm the Scandinavian Diamond Nomenclature grading scale. The ref I cited, I would really prefer to do away with it, if a better citation for the grading scale could be made. Also, present status on the CIBJO, and IDC scales should be checked. I did find one website that broke the CIBJO "Slightly tinted white" into "Very sl..." and "Sligh..". I do not trust this source as there is patently wrong information stated there - (ie the reason color grades "A" "B" and "C" do not exist is because diamonds THAT pure are believed to not exist!). I am not as familiar with the european standards so if you know please help with a quality source.SauliH 07:43, 22 February 2007 (UTC)
 * I like the table, but wanted to let you know that, at least on my screen, some of the longer words are cut off in the middle. For example, I see "Wesselt" and "Top Wesselt" and "Commer White".  Then again, I usually don't browse the internet full-screen, and that can mess up formatting.~  ONUnicorn (Talk problem solving 15:21, 22 February 2007 (UTC)
 * That's what I was afraid of. I will try to get some work done on it tonight. Does it look REALLY bad - bad enough that it cheapens the look of the page? ie should it be taken down for the time being? SauliH 15:28, 22 February 2007 (UTC)
 * No, it doesn't look REALLY bad. It's only 3-4 cells that are cut off, and it still provides useful information and looks nice. I'd leave it up, and just work on it when you have a chance. ~  ONUnicorn (Talk problem solving 15:54, 22 February 2007 (UTC)


 * I have an idea on how to make it work, will attempt a change later tonight.65.248.215.97 01:09, 23 February 2007 (UTC) Ok this was me, computer at work logged me off... SauliH 01:11, 23 February 2007 (UTC)


 * Ok first step was to reduce font-size to 90%. The words I fear will not be read are the "exceptional white" grades... do these read ok now? The next step I am toying with is to start abbreviating... I do not like that option as much - but if I need to go there I will. My sandbox presently has some abbreviations made to it, with a key added in the footnotes.SauliH 04:58, 23 February 2007 (UTC)

There are no UV filters
This article says that diamonds are color-graded "with daylight equivalent lamps, that are UV filtered." This is not correct. Even though UV filters were used starting in the 1970s (when the GIA switched from incandescent bulbs to fluorescent tubes) in 2004 the GIA issued a report on the benefits of blue fluorescence in diamonds and how the uv found in natural daylight can enhance a diamond's appearance. The following year, 2005, the GIA switched over to a different lamp with no uv filters.

Other grading labs soon followed suit.

According to one study, diamonds with very strong blue fluorescence are now over-graded by three letter grades. Another study says it is closer to four letter grades.

This has been the big scandal in the diamond industry since 2005.

The GIA's argument is that these lamps simulate "northern daylight" in conformity with the famous FTC 1938 regulation. The counter-argument is that the "northern daylight" standard is a vestige of the pre-scientific era (going back to 18th-century Antwerp). Also, the GIA's recommended distance between stone and lamp is 8 - 10 inches, even though this distance is not being consistently observed.

This is why so many people these days insist on diamonds with no fluorescence. Unfortunately, this doesn't work either, since the standards for grading fluorescence are so loose that even a stone with a fluorescence of "none" can have enough blue fluorescence to cause it to be over-graded by one or two letter-grades. Zyxwv99 (talk) 13:30, 17 May 2013 (UTC)

References

Accredited Gemologists Association

CIBJO

Professional Jeweler Magazine  Zyxwv99 (talk) 03:06, 19 May 2013 (UTC)

Record price for colored diamond is out of date
Under the heading "Value of colored diamonds", the last portion reads "(the world record) was again broken in 2016 when the Oppenheimer Blue, a 14.62-carat (2.924 g) vivid blue diamond became the most expensive jewel ever sold at auction. It is the largest fancy vivid blue diamond classified by the Gemological Institute of America ever sold at auction; it sold at Christie's in Geneva in May 2016 for US$50.6 million (GBP 34.7m; 56.83m SFr)." (emphasis added) This is incorrect. Sotheby's sold the Pink Star diamond at auction in Hong Kong on April 3, 2017 for just over $71 million. Bricology (talk) 23:15, 9 January 2018 (UTC)

Chameleon Diamonds
This article needs to include chameleon & reverse-chameleon diamonds, a rare green/yellow diamond color (first recognized in the 1940's as a real phenomenon) incorporating impurities that cause it to be photochromic (reactive to light) and/or thermochromic (reactive to temperature) but with the ability to naturally return to its original color absent the stimulus. Below is a brief article about this phenomenon which mentions studies done by the Gemological Institute of America (GIA) starting in 1943. The 2nd link below is a search result from the GIA website on this subject and seems to include links to at least some of those studies. 47.176.126.162 (talk) 01:14, 6 October 2021 (UTC)
 * https://www.diamondregistry.com/education-guides/chameleon-diamond/
 * https://www.gia.edu/search?q=chameleon+diamonds