Trace Elements of the Red Emerald
Colors in gemstones are caused by chromophores: trace metal impurities present during formation which remain trapped in the final chemical makeup. Even the smallest atomic dusting of chromium can have a dramatic impact on color, and the verdant green of Emeralds as well as the luscious reds in Ruby are both caused by chromium. Ever since the first appearance of the red beryl mineral in the public record, Red Emeralds have also been known to contain chromium.
In 1912, Dr. Alfred Eppler first mentioned Bixbite as a suggested name for this mineral in his comprehensive work on gemstones (written in German), where he identified chromium as an element contributing to the creation of red beryl's unique color. A recognized US Government authority, the Utah Geological Survey accepted his findings and published survey notes in 2002 which claim chromium assists in painting this variety.
The peer-reviewed online mineral database Mindat also cites analysis which indicates chromium is partly responsible for this beryl's scarlet shade (Neutkins - 2009). For at least seventeen years, Ray Zajicek has openly advocated a gemological justification for the name Red Emerald, and in 2000 was quoted "pointing out that both red beryl and emerald contain the element chromium."
While investigating red beryl during their tenure as the owners of the world's only commercial mine, the Kennecott Mining Company commissioned an Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) from Chemex Labs in 1994 to identify trace elements present in samples collected from beryl zones throughout the Ruby Violet claims. Chromium levels were tested with a lower detection limit of 1 part per million (ppm) and an upper detection limit of 10,000 ppm. Chromium was noted in all samples, but two were discarded as outliers, which tested above 150 ppm. Chromium levels averaged 53 ppm, but were measured as high as 98 ppm.
Original Spectroscopy Analysis.
Chromium Levels Highlighted in Yellow.
In their 2009 article Gem Formation, Production, and Exploration, Groat and Laurs described the typical environment for Emerald crystallization: "A good example of the requirement for [colored gemstone formation to occur in the presence of] a major element and a chromophore is emerald. Beryl is a relatively rare mineral because there is very little beryllium in the upper continental crust…[but]…chromium and vanadium are more common (92 and 97 ppm, respectively; Rudnick and Gao 2003)". Chromium at any level in Red Emerald stones indicates some will contain higher chromium levels than certain Colombian Emeralds, considering some Colombian Emeralds are tinted by vanadium!
The International Gem Society manages Ganoksin, the world's largest online jeweler information network, which describes Red Emerald as having, "an intense red color…resembl[ing] very fine ruby. Like emerald and ruby, red beryl has chromium as a trace element, but manganese gives it the red color."
If manganese were the sole trace element responsible for the Red Emerald hue, manufactured synthetics colored by manganese would result in similarly-colored gemstones. However, in 1996 William Rohtert reported to the Gemological Institute of America (GIA), "the synthetic displays a more pronounced pleochroism than the natural material, and…is characterized by distinct internal graining in contrast to its absence in the gemstone, where fingerprint inclusions are common." Rohtert reported eleven trace elements in addition to manganese in natural red beryl, which may be the most present in any gem variety (Rohtert - 1995).
If one encounters a red stone ambiguously presented as a ruby, the amateur scientist can inspect dichroism to determine conclusively if the gem is genuine, or not. The Ruby possesses a color which is unique in the entire gem world, and if a hallmark strongly-dichroic Orangish-Red/Purple-Red is observed, there is no doubt of the variety. Of course, the amateur scientist must then determine if the stone is genuine or a synthetic…a gemologist's work is never done!
Ruby's strong Orangish-Red/Purple-Red dichroic color was unique until 1958 when the Red Emerald was discovered, and the number of gemstones with these color-qualities became TWO. This color is absolutely identifiable as THE precious red hue, and the fact Red Emerald SHARES this unique shade is significant. Is it merely coincidence chromium and this extraordinarily particular hue are found together in both occurrences, or is chromium the reason natural manganese-colored beryls do not appear "correct"?
Depth of color in this 2 carat Oval Ring is seen as the Purple-Red at the top
transitions into a fiery Orangish-Red burning in the bottom.
More sources support belief in a chromium crimson, but let there be no mistake: Even if the absurd proposition an Emerald must contain chromium WERE the case, the Red Emerald HAS chromium…but chromium does NOT an Emerald make.
The effect of chromium on Red Emerald color has zero impact on whether this beryl can be classified as an Emerald. The Gemological Institute of America determined an Emerald exists which is colored by a different chromophore (vanadium). Following the same logic, the possibility of a third Emerald colored by yet another chromophore must be considered.
The GIA defines all colors as having THREE components: not only hue, but also saturation and tone. To obtain traditional status as an Emerald, a beryl had to exhibit an intensely-saturated color, or the stone was classified as a mere green beryl. Only the green variety of beryl had intense color, and the green alone was found with overly dark tones. Although the primary hues differ, the same secondary hues (blue and yellow) observed in green Emeralds are also present in the red (when these secondary hues are mixed with a red body color, they appear purple and orange).
The Emerald has intense saturation, dark tones and a hue range spanning from blue to yellow. When the red varietal was discovered, the number of beryl that fit this description rose to TWO.
The Red Emerald is the only beryl with the intense saturation, dark tone
and blue-to-yellow range of hues seen in traditional Green Emeralds.
The presence of multiple hues in Emerald means no single chromophore is responsible for the entire color perceived. The primary tone of a Colombian Emerald is created by the chromophore chromium or vanadium, but the wide range of greens is due to the additional presence of nickel and iron, which causes those secondary blue and yellow tones, respectively.
The blues of sapphire and a wide range of tones are produced by varying levels of titanium and iron, which also creates the blue/purple and yellow/orange secondaries. Iron is responsible for the yellow secondary tones in the Green and Red Emerald.
The Red Emerald contains chromophores responsible for the colors of Sapphire, Ruby AND Emerald. These trace elements combine to produce the color of a Ruby in the body of an Emerald. What more evidence could one require for proof the Red Emerald is one of the most precious gemstones of all time!
The Color of a Ruby.
The Body of an Emerald.
Although collectors are entitled to admire and prefer chromophores of their choosing for any number of reasons, rarity must surely be regarded as a valid basis for one's appreciation. Although the red in American Emerald is created by manganese, we can conclude the appearance of a trivalent manganese during beryl formation is far more rare than growth in the presence of chromium, because there is only one place on Earth where we have ever found this to occur in gem quality!
Each country has their own rules, and the Vienna Gem Center still does not concede non-chromium beryl can be Emerald, claiming, "There are green Beryls which owe their colour [sic] to vanadium, rather than chromium…These stones must not be termed Emerald, but Vanadium Beryls." The Gemmological Association of Great Britain (GEM-A) in London also refuses to recognize these beautiful green beryl gemstones as Emeralds. Neither prohibition has eliminated or reduced the actual presence of African or Brazilian material on the market.
There is a lack of consensus in defining the word "Emerald". There is now, and always will be, different OPINIONS in this world for what an Emerald is. Some of those diverse perspectives also believe in an Emerald that is Red…and their numbers are growing.
I do not consider the presence of chromium to be the one and only factor which determines a gemstone's status as an Emerald. I do not consider color as the solitary trait which defines an Emerald. I do not consider crystallography to be the lone characteristic which classifies an Emerald. And yet the red and green share parallels in all these areas. I examine as many properties of this mineral as observation will allow in an attempt to find features common to other known stones, and the red and green beryls possess too many similarities to conclude they are anything other than the same thing.
The most similar stone to this Red, to the exclusion of all other gems, including the exclusion of all other beryl, is the famous variety we call an Emerald.
The family that glows together, goes together.
Referring to the rarest member of this gemstone family by a name connoisseurs will not recognize denies them the knowledge and enjoyment of a new gem, does a disservice to a treasure already abused and fails to bring any credit to the industry.
The customer must always remain free to make their own rational market decision; lovers and consumers of red gemstones have the legitimate right to know our nation has a version of their favorite gemstone, now in their favorite color.
ALL REFERENCES BY DATE OF INFORMATION
Chemex Labs. Red Beryl Sample Analysis: A9417286, Kennecott Exploration Company - June 10, 1994
Rohtert, William R. Internal Memo: Synthetic Red Beryl from Russia, Kennecott Exploration Company - August 14, 1995
Rohtert, William R. Gemological Institute of America Correspondence: Donation of a 1.54 carat Synthetic Red Beryl, Kennecott Exploration Company - March 21, 1996
Ege, Carl. What Gemstone is Found in Utah that is Rarer than Diamond and More Valuable than Gold? Utah Geological Survey, Survey Notes Volume 34, Number 2 - September 2002
Groat, Lee and Laurs, Brendan. Gem Formation, Production, and Exploration, Elements Magazine, pp. 153-8 - June 2009
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