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What Color Is Pigeon’s Blood


“Asking to see the Pigeon’s blood is
like asking to see the face of God”  (Update 2016)


Richard W. Wise, G.G.
©2018

About once a month on one of the gem forums
someone asks the question:
“What color is pigeon’s blood.”

pg1The real question is, of course, “what is the best color in ruby.” Although I cover the question in some depth in my book; Secrets of The Gem Trade, The Connoisseur’s Guide to Precious Gemstones, it appears that a few people have yet to read the book. (pictured above a gem quality 2.09 carat natural old mine Burma ruby with a GRS “pigeon’s blood certificate)

The short answer is simply that rubies should be red. Problem is there are almost no visually pure color in nature so, we speak of a mixture of colors. In gems, we normally speak of a primary and a secondary color or hue. Gems may have more than two hues but it it is difficult for even the most discerning connoisseur to see more than two. Still a ruby must be predominantly red, that is, have a primary red hue. Put another way in the color mix, red must be at least 51% of the hue mixture. If its not red its not a ruby. Any member of the gem family corundum that is any color other than red we call sapphire.

Wisdom from the Old Mine:

Ruby may exhibit one of a few possible secondary hues. These are: pink, purple and orange. Purple and orange are the hues immediately adjacent to red on the color wheel. You will never find a ruby with a green secondary hue. Pink, a paler less saturated red is also possible. The finest color or pigeon’s blood exhibits a purple secondary hue. Why purple, there are two good reasons; one historical and the other based upon color science.

pg2This historical explanation I owe to Vincent Pardieu. Vincent began by studying gemology in Burma and he found a dealer who explained “pigeon blood” to him. The Burmese coined the term. Purple is a hue that falls between blue and red on the color wheel. It is known scientifically as a modified spectral hue. The Burmese set gems in pure gold which is a a very rich yellow color. Blue is the compliment of red. Complimentary colors are those that cancel each other out. So when a purplish red ruby is set in yellow, the yellow of the metal cancels out the blue in the purple leaving behind, guess what an almost visually pure red.(pictured above a 1.63 carat gem quality old mine Burma ruby with a GRS “pigeon’s blood certificate). So the goal for the Burmese is red, pure red!

I wrote my book several years before I met Vincent in Bangkok. However, I reached the same conclusion by applying a logical analysis. My reasoning goes something like this. Color Science teaches that the color red reaches its optimum saturation (brightness) at a fairly dark tone, somewhere about 80%. This is not opinion, it is measurable scientific fact. If you consider that 100% tone would be pure black, 80% is pretty dark. Pink and orange on the other hand reach their optimum saturation at fairly light tones. Pink obviously as it is by definition paler (less bright). Orange reaches its optimum saturation at between 30-40% tone.

Purple reaches its optimum saturation at around 60% tone. Now, if you add a light pigment to a dark paint you would obviously lighten the overall effect. Same is true in transparent media. The optimum tones of red and purple mix fairly well both being both dark in tone. The purple unlike the pink does not dilute the red. Pink and orange would lighten the red thus reducing the overall saturation of the pinkish-red or orangy-red color. Purple reinforces the red, orange and pink dilute. Make sense? Not everyone agrees. Some connoisseurs like a bit or orange. They feel it frames and pumps up the red hue. A good point if you consider the effect of orange in red spinel. Be that as it may, for good historical as well as scientifically verifiable reasons, orangy red is not pigeon’s blood.

New Sources, New Insights:

In 2016 I published the second edition of Secrets Of The Gem Trade, The Connoisseur’s Guide…  During the preceding fourteen years much had changed in the ruby market.  Winza (Tanzanian ruby) had come and pretty much gone, Mong Hsu had stopped producing, but Mozambique had become a major new source.  The required an extensive rewrite of my chapter on ruby.

In 2008 a modest source was discovered near the town of Winza, followed by two strikes in Mozambique; the first in Niassa Provence near the village of M’awize in 2009, the second near the town of Montequez in Cabo Delgado Province. The best material comes from Namahumbire, near the town of Montepuez. In the trade it’s known as Montepuez ruby.  A majority of stones in the marketplace are from a four hundred square kilometer mining concession at Montequez, a partnership between the Mozambique government and Gemfield’s,a publicly traded company based in London.  These new sources produce gems with characteristics that are similar, but distinctive.  For a more in depth discussion, I refer you to my second edition.

A Note on Images:

The first image above is of a 2.09 carat Burmese natural ruby from the old min at Mogok. This stone has a bit purer red, exhibits less purple than the second stone, a 1.63 carat gem from the same mining area. Both, however, have been grading “Pigeon’s blood” by GRS, Swiss Lab, Bangkok. As you might imagine this lab sees an awful lot of rubies. Both stones are from the Mogok Valley, this is the place, going back to the Bronze Age, where the original stones were mined back when the term pigeon’s blood was coined. A lot of the gems currently in the market are from a new mining areas Mong Hsu that is about half way between Mogok and the Thai border. Mong Hsu stones can certainly be pigeon’s blood color but since we are talking about a historical term I thought it best to use illustrations from the old mine.

 

11 Responses

  1. K shivaramachary says:

    I am interested in pigeon blood ruby

    • carl says:

      Add me on facebook carl k cox II

    • Aubrey says:

      Not a pro when it comes to gems but I would like to comment on the color science thing. Blue is not the compliment of red, but of orange; it is green that compliments red. So I guess this changes the entire formula?

      As for saturation, it is totally different from brightness. The former pertains to the amount of hue or pigment, while the latter pertains to the amount of light.

      Anyways, this article is interesting.

  2. Alice says:

    I just heard about bloodstone that it is also called a stone of pigeon blood because of the red spots on it but I am so glad to study this whole article about pigeon blood ruby I want to study more about this ruby willingly 🙂

  3. Noel Dejoras says:

    I found A pegeon blood ruby inside a small pocket of a denim pants brand name Lee . I try to test it if it is true. I rub its flat surface to a mirror when it stick then it is real. And it did. That is how our ancestor check rubies in their time.

  4. Robin says:

    Burma is generally the best known for the best rubies even though Niassa Ruby from Africa is also a beautiful red but is Fisher filed I haveI bought 25 years ago it looks pastel ,but it’s a Ruby because of the iron in it and it glows under a Incandescent light it’s awesome

  5. Aubrey says:

    Not a pro when it comes to gems but I would like to comment on the color science thing. Blue is not the compliment of red, but of orange; it is green that compliments red. So I guess this changes the entire formula?

    As for saturation, it is totally different from brightness. The former pertains to the amount of hue or pigment, while the latter pertains to the amount of light.

    Anyways, this article is interesting.

  6. Alan Whipple says:

    I have a stone that I broke up on an anvil. There is one piece that I tried to break it had a reddish Trigon on it on the outside it’s got a purplish dark purplish hue to it. My friend and his sister had never seen anything like it before. Their whole yard is a rock garden.

  7. Morrisa says:

    I really enjoyed this pigeon’s eye article, I love learning about gems. As a new comer its helpful.

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