February 22nd, 2012
by Richard W. Wise, G.G.
©2012
Tucson; Life As A Treasure Hunt:
 There is more than one way to build a gem collection. One of the great things about my job is that my life is a treasure hunt. Seeing all of the newly acquired treasures spread out on the desk is ne of the most rewarding parts of the whole experience. Only then do you get a real sense of what has been accomplished. That is why Rebekah and I make the Tucson pilgrimage year after year.
Show & Tell:
Over the past twenty-five years, we have made buying trips all over the world, but there is still something special about Tucson. This year’s show was a mixed bag. There were no exciting new finds to rock the gemworld. Prices were strong reflecting the continued erosion of the dollar in overseas markets. There was a great deal of Ethiopian opal available and spinel continues its rise to stardom. Let me share a few highlights from our trip:
Spinel:
 Speaking of Mahenge Spinel, with prices skyrocketing for the pure pinks, mixed hued gems like this beautiful 2.02 carat orangy-pink "padparadscha" spinel, are still comparative bargains. Inventory #10604 Two factors, the discovery of quantities of bright Cobalt blue spinel in Vietnam and hot Mahenge pink in Tanzania in the early part of the last decade have supercharged demand for this previously little appreciated gemstone. Why is a mystery, spinel has always been a good choice, it is highly crystalline, durable and comes in many hues, but since these two discoveries, demand and price have escalated dramatically.
According to statistics gathered by Dr. Adolf Peretti, President of The GRS Lab in Bangkok and presented to the Accredited Gemologists Association annual seminar in Tucson, spinel prices that have been rising steadily over the past five years have jumped by an astonishing ten times is just the past two years. Though most of this price increase is in the higher end of Cobalt blues and Mahenge pinks, prices for all colors have followed the trend.
Tahitian Black Pearls:
Ever since my first trip to the pearl farms of the Tuamotu Islands, north of Tahiti, I have been entranced by the beauty of black Tahitian pearls. Black pearls, of course they are not really black, in color they are varying tones of gray. Black pearls carry with them an air of mystery and are a wonderfully sophisticated alternative to white pearls. Just as flexible fashion-wise, anywhere you can wear white, except perhaps on your wedding day, you can wear black pearls.
Exceptional pearls are described as having life! Life is an elusive quality. First the pearl must have a flawless skin and high luster, but not only that, a steel ball-bearing has great luster, the other component is overtone and the black pearl has the finest, most distinct overtone of any pearl variety. What is overtone? Rather than indulging in long winded explanations lets see if this image will replace a thousand words. Pictured below right are three top quality Tahitian pearls.
Note the lovely mirror like luster and the rose/green overtones of the pair to the left. Often confused with color, overtone is ethereal, it hovers and clings to the pearl like an early morning mist. This combination is known as peacock. The single pearl to the right is a delicate rose.
Under the microscope, the skin of a pearl resembles a shingled roof. Overtone is the result of light refracting through tiny translucent prismatic “shingles” of nacre, made of aragonite, a calcium carbonate, nacre secreted by the host mollusk makes up the pearl’s essence.
 12.5mm Tahitian Black Pearls of exceptional quality. The pair to the left exhibit a peacock overtone, the gem to the right is a delicate rose pink over a slightly darker almost black hued pearl.. Inventory #10596
We are used to seeing white Japanese akoya pearls with a distinct pink overtone, but that is normally false. Akoya pearls are normally bleached white then dyed pink. The overtone that you are seeing here is completely natural and is the distinguishing feature of the Tahitian Black Pearl.
the normal overtones in Tahitian pearls are rose, green, blue and purple along with various mixtures. Green is the most common, blue is rare and purple almost non-existent.
We also managed to obtain a 9mm strand of multi-overtoned black pearls. These strands alternate the various overtones. Pearls with distinct overtones have a high degree of translucency which means that the pearls will actually pick up subtle hint of color from the dress or blouse that a woman may be wearing.
 Flawless and perfectly matched rounds, this 9mm strand of black Tahitian pearls exhibits the characteristic blue, green and rose overtones. Inventory #10606 Like to hear more from GemWise? Interested in the crème de la crème of gemstones. check out the table of contents to the right.
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Tags: blue sapphire, cobalt blue spinel, Ethiopian Opal, Mahenge spinel, Spinel, Tahitian Black Pearls, Tuamotu Islands, Tucson gem shows
Posted in Ethiopian Opal, Prices, Tucson Gem Show, collecting gems, gemstones | 2 Comments »
February 11th, 2012
by Richard W. Wise, © 2012
Dénoument, or, The Party’s over….
Well Tucson 2012 is finished, at least for us. The show that started it all, The Tucson Gem & Mineral Show (TGMS) closes today but believe it or not there are a few diehards still hanging on.
In the last post I wrote about golden yellow topaz from Brazil. I say Brazil because virtually the only site for commercial quantities of topaz is a twenty square mile area encompassing the Brazilian town of Oro Preto. The name means black gold and this small town was one of the richest on earth in the 1850s. Those days are long gone but the quaint cobble-stoned streets and lovely architecture has caused the United Nations to designate it a World Heritage Site.
Golden Yellow Topaz From Oro Preto:
Most topaz is cut into elongated pear and oval shapes. This is due to the fact that the C axis normally has richer color than the AB axis of the topaz crystal. These long shapes allow the C axis color to bleed up into the cut gemstone gathering a darker toned hue toward each end of the gem.
 5.07 Carats Golden "Canary" Yellow Topaz. A matched pair from Oro Preto Brazil. Note the richer more intense yellow gathered at each end of the gemstone. Photo: Jeff Scovil Though it is arguably the least expensive color in topaz, yellow is still quite rare and I have seen very little of the golden yellow variety of this gemstone in some years. So I was very please to be able to acquire this exceptionally vivid pair of perfectly matched stones.
Topaz is available in a continuum of colors. Generally the price increases with the addition of orange and pink but the yellow variety has a liquid, feminine softness of hue that is unique to this variety. Pictured at left is a particularly fine example, the yellow is rich and pure intensifying towards the tip of the pear.
Stay Tuned!
Posted in Brazil Gemstones, Golden Yellow Topaz, Topaz, Tucson Gem Show | 2 Comments »
February 6th, 2012
by Richard W. Wise
©2012
Malaya Pure and Simple:
 Rough and cut; malaya or rhodolite? Here the pink hue dominates in this pair of brilliant cut garnets from the new find in Tanzania. Note that the two stones, with identicutting and matching appear quite different to the digital eye of the camera: Photo: Jeff Scovil Much of the new Tanzanian garnet is being touted as “imperial” a term that sounds very good but has no actual meaning. Just to set the record straight, this new garnet is malaya pure and simple. It exhibits a brown primary with a pinkish secondary hue. Although pink is the preferred secondary in all brown gemstones, the brown dominates. I saw one pair of very well cut round brilliants that showed brown and pink on alternate facets, really odd! I will not be brilliant cutting my rough! You will often hear the term imperial, imperial topaz is another example.
Golden Yellow Topaz:
One vendor had a nice supply of yellow Brazilian material, something I have not seen in a long time. Though arguably the least expensive color in topaz, it is really quite rare. This topaz is quite beautiful, with a soft canary yellow hue that is particularly lovely when cut in the pear and oval shapes that gather and concentrate the yellow towards each end of the gemstone. Topaz shows its strongest color on the C axis of the crystal so symetrical cuts, rounds and cushions usually appear washed out when compared to ovals and pears. The pear and oval shapes allow the C Axis to bleed through at either end.
The Digital Eye:
As always, once I find a few treasures I bring them to photographer Jeff Scovil who sets up at the show each year. A picture may be worth a thousand words but bear in mind that nine hundred ninety nine of them may be lies. It is always interesting to watch the contortions Jeff is forced to go through to digitally reproduce what the eye sees. Orange stones are a particular problem. Brown is a dark desaturated orange, so if the light is just wrong, an orange gem can appear distinctly brown as in the digital image reproduced here.
 Surrounded by reflectors, celebrated gem photographer Jeff Sovil attempts to evenly light and digitally render what the eye sees in a cushion cut yellow topaz.. Note the white card that blocks the black lens reflection at upper left. Photo: Richard Wise  It happened in the old days too. A beautiful pure orange spessartite garnet turns brown in an old fashioned slide photograph. Photo: Jeff Scovil Yellow topaz is an interesting case in point, the soft golden hues, particularly at the point of concentration will often appear brownish in a digital images.
Today’s online shoppers who take the easy path of comparing image to image rather than stone to stone do themselves a great disservice. In the upper reaches of quality, the subtle differences that separate the exceptional from the merely fine or the fine from the good are often impossible to capture in a photograph. Thus, the buyer congratulating himself on choosing the lowest price, sight unseen, may embrace the mediocre without even knowing the difference.
Tags: Brazil Gemstones, Tucson gem shows
Posted in Brazil Gemstones, Garnet, Golden Yellow Topaz, Topaz, imperial topaz | No Comments »
February 4th, 2012
by Richard W. Wise
©2012
This is our 27th year at Tucson. The term Tucson Gem Show is more than a bit of a misnomer. It began is a single show and has since grown into a colossus of forty five separate gem shows depending upon how you count them. Whether you are a connoisseur interested in the best of the best in sapphire of a Desert Rat looking to expand your collection of coprolite, there is something for everyone at Tucson.
Our first stop, as always was the Pueblo Show. Hotels in Tucson change hands and names with a confusing regularity. The Pueblo Show is held at what is now known as The Riverpark. When there has been a new strike, the results first find their way to the Pueblo with furtive looking gentlemen carrying large satchels of rough booth to booth. This year is a disappointment. There has been little of note since the discovery of the discovery of Ethiopia’s Wegel Tena Opal fields.
There is still a good supply of Ethiopian opal but the buyer must exercise care because, though Wegel Tena material has developed a reputation for stability, some material from other locations is quite unstable and will soon craze. About the only new thing in rough gems is Malaya garnet.
First discovered in Tanzania in the mid 1960s, Malaya, the Swahili word for outcast or whore, Malaya is one of a class of garnet varieties that exist on a refractive continuum that has made a hash of the traditional garnet variety classifications. The colors of Malaya run from a dark toned “brick” orange to a medium toned pinkish-brownish-orange—sort of a honey color that can be quite lovely. As a rule of thumb the more pink, the better. Occasionally gems can be found which a a pure pink, but the refractive index of these examples may move them beyond the name Malaya.
There is a fair amount of nicely pinkish water worn pebbles, 6-8 carats in the rough at reasonable prices. I purchased a few which, with luck should yield 2-4 carat gems.
Stay tuned!
Posted in Ethiopian Opal, Garnet, Opal, gem value | No Comments »
January 10th, 2012
©2011 by Richard W. Wise, G.G.
First off, Gem-e-Price is the first grading/pricing software that I have evaluated and working with it was a lot of fun. With the recent addition of colored diamonds, Gem-e-Price is now able to offer a price structure for just about all species and varieties of colored gemstones.
Gem-e-price offers three ways to approach the evaluation/pricing process. I say evaluation because, although gem-e-price is sold as pricing software, the ability to select quality is a necessary precondition for determining price.
Ease of Use:
The software is easy to use. First you are presented with a fairly clean screen with buttons and drop boxes. There are three tabs; Fancy Search, Price List and Price Calculator. The default screen, Fancy Search allows you to select a gem variety, size, shape, weight, clarity, treatment.
 Gem-e-price Home screen showing range of colors in yellow diamond. Unfortunately it didn’t take long for the first bug to appear. Once you select “color” (primary hue) and “modifier” (secondary hue) and move on to shape, you quickly realize that though you can select your shape from a graphic series, only two shapes will actually appear in the gallery, select round or square cushion, choose any other shape and square cushion is shown.
The images, which in the colored diamonds section covers the basic grades, fancy through fancy dark, are not pictures of actual gemstones or photographic images at all, they are graphic representations. When I first saw these during the introduction of gem-e-price for colored gems, I referred to them as grading by cartoon. However, one function of the software helps overcome this lack of veracity to some degree. Once the color has been selected, say yellow, the “Fancy Ruler” button to the right will take you to a screen with a spectrum representing all colors, from there a “Select Color” button in the center of the screen takes you to a new screen with all permutations of the given color (hue): brownish yellow, brown yellow, orangy yellow and so forth. You get a good relative overview of what the graphic range is supposed to represent and is useful for honing in on the appropriate nuance of color.
 Gem-e-price screen showing range of primary and secondary hues in pink diamonds. It also provides you with a more or less universally accepted color descriptive shorthand, e.g. VpB (vivid purplish blue). I should add that you are able to upload, at the home screen, an actual image of the diamond that you wish to compare and that image follows you from screen to screen.
Nomenclature Issues:
Is the pricing accurate? As Shakespeare said, “aye, there’s the rub.” The answer is yes, no and sometimes. I compared the Gem-e-price with a couple of my own diamonds, then called colored diamond expert Stephen Hofer author of Collecting and Classifying Coloured Diamonds and compared various price lists, pink, gray and blue diamonds generated by the Gem-e-price software. The prices made no sense at all until in a conversation with Gem-e-price developer, Menahem Svedermich, he revealed that the price is pegged fairly low. This will require a bit of explanation.
The point I make in my book, Secrets Of the Gem Trade, is that all fancy vivid diamonds are not created equal. GIA’s colorless diamond grading system has 24 grades, the GIA colored diamond grading terminology has only between 5-7 depending upon the hue. These are fancy light, fancy, fancy intense, fancy vivid, fancy deep and fancy dark. In the vivid category, for example there can be high, medium and low vivids depending upon the saturation/tone of the hue. Gem-e-price assumes a 1-5 saturation grid at each level and pegs its price to level 2. Why not the median? Good question! Well, one week later, Gem-e-price has been updated, it now sports three price levels for each color grade, Regular, Fine and Extra-fine categories and these have helped to better define price levels.
Pricing Accuracy:
With Hofer’s help I took a look at a one carat Fany Intense Pink diamond( FIP). A two thousand dollar spread, in pink diamonds, hardly worth mentioning, the price was spot on. I then went to a 0.70 FVY-O from my own inventory. This is a problem stone, The GIA grading report calls it Y-O, to me its a orangy yellow (oY). So, I tried it both ways. The Yellow-Orange price was way out of the box, the Orangy-Yellow was pretty close to my actual cost. Next I tried a 1.75 Fancy Intense Blue IF which Hofer described as a top stone. The Gem-e-price was between under Hofer’s price by between 100-200,000 per carat—sounds like a lot but we are talking blue diamonds here so it is fair to say that Gem-e-price is in the ballpark. I did some further work, switching over to colored gemstones I priced out emerald, ruby and sapphire. The emerald and sapphire prices came out in the zone, the ruby price, we are talking super-unheated-gem in one carat sizes came out very high. I asked Antoinette Matlins author of the second best book on colored gemstones—opps there goes my Bonanno award—she checked my price and reported results that were similar to mine.
Overall Evaluation:
Overall I like it. Is it perfect, no! It is designed for professionals, in the hands of someone without a wealth of experience it could be a potential disaster, but then what isn’t? Gem-e-price is a useful tool, its got a few bugs, but it is getting better, Svedermich and his team made adjustments as I worked and will, I am sure, continue to improve the product. I like the price grids! A subscription with monthly updates is $300.00 per year and, in my opinion, well worth the price.
Tags: color evaluation, colored diamond prices, gem grading, gem pricing, gemstone prices
Posted in Colored Stone grading system, gem value | No Comments »
December 6th, 2011
by Richard W. Wise, ©2011
Dateline: Hong Kong
 Current world record holder, 26.41 Carat Kashmir Sapphire Courtesy: Christie's A New World’s Record:
November 29th, Christie’s Auction House, Hong Kong, sold a 26.41 carat Kashmir sapphire for 3,838,508 or $145,342.00 per carat. This sale establishes a new world’s record price of Kashmir sapphires sold at auction, besting the former world’s record also established at Christie’s (New York) for the 22.66 carat Hill Sapphire which sold in April 2007 for $3,064,000 or $135.216.00 per carat.
Kashmir sapphires were originally found on a small hillock 13,000 feet up in the mountains of the now disputed Indian state of Kashmir in 1881-1882. The harsh conditions at this altitude meant that the mines could only be worked about one month per year. By 1887 the output of the mines had diminished substantially. The original lessee abandoned the diggings in 1905. Four other groups had a go at it with little success and the sites were more or less abandoned in 1928. A bit of material is still occasionally found, alluvial material at the bottom of the ridge, but the major production of Kashmir sapphire lasted a mere six years.
Kashmir stones are highly esteemed for their color, a vivid purplish blue, a hue often described as “cornflower blue.” Others, most notably Richard W. Hughes, author of the seminal book Ruby and Sapphire, describe the finest color as a Pepto Bismol bottle blue. The problem with this characterization is that Pepto Bismol bottles are now pink—but there are those of us who are old enough to recall when the bottles were a bright medium blue. I recall seeing only one stone of this description and it hailed from Sri Lanka.
Kashmir’s famous characteristic, however, is the silky, milky or fuzzy texture that somewhat diminishes the diaphanity (crystal) of the stone. Myriads of tiny inclusions that resemble dust caught in a ray of sunlight or a sub-microscopic milky way, will, when present, diffract and refract the light, causing the stone to take on a velvety glow. Similar inclusions are sometimes found in gems from Madagascar and Sri Lanka, but absent geographical certainty, these “Kashmir type” sapphires do not command nearly the price of those with old mine provenance. The current record holder was accompanied by four laboratory reports certifying Kashmir origin. This, of course, begs the question: If gems are all about beauty and sapphires from other locations have all the characteristics of the finest Kashmir, why does anyone care where the stone is from? The short answer is branding. The market recognizes a value in stones from the original mine. It is also fair to say that although stones can be found with the characteristic glow, very, very few approach the pinnacle of Kashmir color. I have only seen two stones that can be described as #1 Kashmir color and both were from the old mine.
 What a difference a light makes; the current record holder before a re-cut shaved a single carat. Note the large culet visible through the table and the characteristically velvety texture or crystal. Photo courtesy Stone Group Labs. Rapidly Escalating Prices:
Kashmir prices have been increasing steadily since the late 1980s. According to connoisseur and author Benjamin Zucker, a twenty carat fine quality Kashmir sapphire was worth $25,000 per carat in 1976, though I recall an exceptional stone that sold at auction in the early 1980s for $12,500 per carat. By the turn of the last century prices for extra-fine examples at auction passed $100,000 per carat. Pricing must be taken with a grain of salt. Given varying qualities, the vicissitudes of auction houses, and the lack of any real standardized grading system, it is difficult to compare stone to stone.
Prices for premium gemstones, fancy color diamonds, type IIa colorless diamonds, ruby, sapphire, emerald and lately spinel, have all increased markedly since the 2008 bust. This can be traced to a lack of confidence in paper currencies, generally, and the dollar and Euro in particular.
Connoisseurship–Opinions Vary:
Bear Williams of Stone Group Labs, the first gem laboratory to evaluate the new record holder, was impressed. “My hair kinda stood up on end, it had some sort of magic,” he said describing his first look at the sapphire. When Williams saw it, the stone weighed over 27 carats before it was re-cut slightly and re-polished. From all indications the stone is quite superior to the Hill Sapphire, which American Gem Labs President Christopher Smith described as a “nice stone.” in 2007. Smith rated the former record holder, the Hill Sapphire, at an 8-8.5 on a 1-10 scale. Williams puts this new one well into the 9s, “maybe a 9.8″ he says. Chris Smith at American Gem Labs, who did a full quality evaluation, gives the stone an overall Total Quality Integration Rating (TQIR) of Exceptional and a color grade of 2.5 (1-10 scale). Note that AGL’s TQIR factors in rarity, together with quality factors. A five carat Kashmir or the same quality would be graded Excellent.
Tags: Kashmir sapphire, sapphire auction record
Posted in Gem History, Kashmir sapphire, collecting gems, gem labs, gem value, gemstone investment | 13 Comments »
October 26th, 2011
by Rebekah V. Wise
©2011
“Silver is the best material we have; silver has this wonderful shine like moonlight;
a light taken straight from a Danish summer’s night when covered by dew;
silver can look like magical mist. ”
Georg Jensen
My love affair with Georg Jensen and his jewelry began some thirty years ago in that mecca where everything jewelry is possible—New York City. In those early days I had fallen head over heels in love with Scandinavian silver jewelry.
As a buyer and collector, it did not take long before I could see and feel the difference between Jensen silver and all other vintage silver jewelry. The rest of the story, as they say, is history.
Fast forward to the present. Not long ago a client asked to see a Jensen piece. I proceeded to tell her it was designed by Georg Jensen. “Who’s that?” she asked, slightly offended that I seemed a little surprised she didn’t know.
Under-appreciated and under-esteemed—even as the 20th century’s most renowned silversmith—this vintage Jensen bracelet with moonstones inextricably drew in a totally uninitiated young woman who looked, and understood–the difference.
 Early Jensen Arts and Crafts Brooch with Red Amber Collectors and aficionados of vintage Jensen silver jewelry understand! Beautiful to look at, beautiful to wear; the designs just have a look—elegant, understated, a patina and luster to the worked silver that is unique.
From the early Skonvirke (Arts & Crafts) buckles, hair ornaments, and brooches to the most abstract modernist necklaces,
 Henning Koppel modernist necklace Jensen the man and Jensen the company have made major inroads into 20th and 21st century design. His influence is far-reaching, his jewelry designs copied and reference all over the world, easily discernible in 1940’s-50’s jewelry from Europe and North America.
Jensen opened his workshop in 1904 and started making jewelry, concentrating on small items which required little initial investment. Flatware and hollowware followed only later when he had acquired capital. The 1st quarter of the 20 century was Jensen’s heyday, especially the decade of 1908-1918, a period during which he was so happy in his life and productive in his designs that he reached the apogee of his artistry.
Unusual in a workshop, Jensen gave free reign to his designer/silversmiths, designs were credited not only in Jensen’s name, but also in the individual artists’ names. This created an atmosphere of kinship within the ranks, and an artistic freedom that made for the unbridled flow and exchange of ideas.
Unmistakable in their Arts & Crafts ornamentation, these early designs define what we have come to know as the “Georg Jensen Style”, his designs replete with leaves, flowers, grapes, insects and birds. Set with inexpensive gemstones such as coral, amber, lapis, and moonstones, he created jewelry for the up and coming middle classes to enjoy and wear—pieces that were practical as well as beautiful—pieces that were also works of art. No mass production, each piece was made one at a time.
Jensen’s early designs are iconic, his early training as a sculptor evident in the treatment of the silver. Hand-wrought and modeled like miniature sculptures, the silver was often worked with repoussé and chasing, the highs and lows of the metal glinting from the strikes of the hammer. Jensen’s silver looks and feels unmistakable: not only the working of the metal and the patina that vintage pieces achieve over time, but also the interaction of metal and light as light bounces off the leaves, tendrils, and curved silvery surfaces back to the eye. One can see Jensen’s hand, his poetry, in the fashioning of the metal.
Although Jensen died in 1935, the company he founded has evolved and is still evolving. Ownership, shareholders and partners have come and gone, as have the many designers who over the decades designed under his name. The “Georg Jensen Style” lives on; many of his classic early designs are still produced, sharing gallery space with designers of the 1940’s, 50’s and 60’s he himself never met (Henning Koppel, Vivianna Torun Bulow-Hube, Nanna and Jorgen Ditzel, Astrid Fog, Bent Gabrielsen to name a few) as well as with contemporary designer/silversmiths such as Ole Kortzau, Anette Kraen, Erik Magnussen, Kim Naver, Regitze Overgaard, and Alan Sharff.
Importance, rarity, desirability: is an older piece worth more than a new one? Rarity depends on scarcity. Older pieces with early hallmarks are desirable as are designs no longer in production. The hallmarking system is more or less orderly, although marks can be a bit confusing. We value the older pieces for many reasons, but we also look forward to the future and to Jensen’s contemporary designs–tomorrow’s masterpieces.
 Contemporary Jensen: White and Yellow Gold Fusion Rings References for this article: “Georg Jensen Jewelry (Bard Graduate Center), “Danske Smykker” by Thage, “Georg Jensen Silversmithy—77 Artists, 77 Years” (Renwick Gallery 1980), “The Unknown Georg Jensen” (Georg Jensen Society) and “Georg Jensen” by Janet Drucker.
Tags: arts and crafts, Danish jewelry, Georg Jensen
Posted in Georg Jensen | 2 Comments »
July 20th, 2011
 Color temperatures a various types of lighting. 5500-6500 is the Kelvin temperature of daylight. GIA uses a 6200 Kelvin light source for diamond grading. by Richard W. Wise, ©2011
New Technologies May Require Changes is How We Look At Gems:
In 2007 amid little fanfare, Congress passed a law that required that the efficiency of that iconic household standby, the incandescent light bulb, be improved or perhaps accept its doom. The bulb has been around a long time and the technology has remained virtually unchanged since it was invented by Thomas Edison in 1881. Turns out the old bulb is a real energy waster, only 10% of the energy used is given off as light, the rest is dissipated as heat. Though some called it the death of the incandescent light bulb, Congress merely dictated an increase in efficiency, 20% by 2014, 60% by 2020.
Though the efficiency standards do not state what is allowed, such a dramatic increase in efficiency is bound to require new technologies which are likely to mean changes in the light spectrum produced by whatever technology replaces the old standard. No one has given much thought to the consequences this will have in the gem trade. The new standards are scheduled to take effect this January.
In the evaluation of quality, gemstones have been traditionally viewed under two light sources, noon daylight or more lately daylight equivalent fluorescent lighting and plain old incandescent (in the 19th Century it was candlelight). A stone that looked good by day but muddied up under the lightbulb is taken to be inferior to one that holds its color in both lighting environments. In 2003 I published a book, Secrets Of The Gem Trade, that divides gems into daystones and nightstones. The terms refer to gem varieties that look best under a given source. This seemingly bright idea may mean dramatic reductions in oil imports, but wait! What about the gem business, what’s a connoisseur to do?
The Tea Party To the Rescue:
Well our worries may be over, just last week the House passed legislation to deny funding to the law. Apparently the bill’s original Republican sponsor, Texas Representative Michael C. Burgess had an epiphany. He has seen the, ah, light. “The government has no right to tell me or any other citizen what type of bulb to use at home,” no matter how much energy it might save says Mr. Burgess. We have the right to waste all the energy we like in the privacy of our own bedrooms, says so in the scriptures.
But seriously folks! Sooner or later, new, more efficient types of lighting are bound to replace the old standby. Will there be a new standby? Probably not. We are pretty much at the point where the type of lighting used will be dictated by the setting that it is used in. Call it dial a light! At that point will gem grading light be standardized. To some degree it already has. Most laboratories use some artificial version of daylight. The Gemological Institute of America (GIA-GTL) uses a 6200 fluorescent bulb, American Gemological Labs uses a 5500 Kelvin bulb. What is the next step? Stay tuned to GemWise.
Book Review: The Colour of Paradise, The Emerald In The Age of Gunpowder Empires
Kris Lane
The Colour of Paradise, The Emerald In The Age of Gunpowder Empires
280 pages including appendices
ISBN: 978-0-300-16131-1
 The history of the gem trade is a difficult research topic because gemstones are very small objects of great value that have been highly sought after for millenia by rich and powerful people looking for wealth that was portable and easily concealed. The trade itself has been controlled for centuries by minority groups, often oppressed minorities, Jews, Armenians and Indians for whom secrecy was a proven form of self preservation. Kris Lane is a historian, a Professor of History at the College of William and Mary. In The Colour of Paradise, Professor Lane focuses very well honed research skills on the history of the emerald, one of the rarest, most mysterious and highly valued of all gemstones.
The book contains no particularly major revelations. Most historians of the trade are aware that India’s so-called “old mine” emeralds were, in fact, Colombian emeralds imported by the Spanish into India in the Sixteenth and Seventeenth Centuries. Lane’s contribution is to meticulously document both the early history of Spain’s brutal exploitation of Colombia’s indigenous people and its gem wealth. He gives us a well documented overview of early trade routes and uncovers some very interesting and original information concerning 16th Century production; methods and emerald values.
Lane begins with the 16th Century and follows emerald production in Colombia right up to the present, with a good account of politics and production into the 1990s.
All and all this well organized and well written account brings real clarity to a relatively murky area of history. The book also contains detailed appendices estimating early emerald at Muzo, relative values of emerald and diamond in Europe in the 17th Century and an extensive bibliography. The author has uncovered several original accounts that have until now been unrecognized. Highly recommended.
Tags: book review, gemstone lighting, grading gems, investment gems, The Colour of Paradise
Posted in Colored Stone grading system, Gem Books, Gem History, Gemstone lighting, collecting gems, grading and pricing Columbian emerald | 6 Comments »
May 19th, 2011
by Richard W. Wise, G.G.
©2011
You Just Can’t Hide Those Lying Eyes:
 Image A: Before photoshop, this is the image the camera saw. Photo Courtesy Precision Gem In my first post on this subject, I made the point that making a purchasing decision or merely comparing prices by comparing images is fraught with difficulty. Photoshop and other similar programs are a good part of the reason why. The two images to the left illustrate the point. Image A is a custom cut Mali garnet. Based on the image, the stone appears to be a slightly greenish (10% yellow light toned garnet of medium saturation, not bright but not overly dull with a slight gray mask.
In Image B of the same stone, the original image has been altered by a simple tweak of the Saturation Enhancement Tool in Photoshop. The green secondary hue now appears more prominent, perhaps 15-20%. The big change, however is in the level of saturation. The color must now be described as vivid effectively doubling the value of the stone. The only hint that this is the same image is that the background in image A is slightly cooler (grayer) than the background in image B. However, if the photographer simply took two shots under the same lighting he could easily disguise that fact. Backgrounds can also be removed or replaced with a uniform black. Assuming that these two images appeared at similar prices on separate websites, an online bargain hunter would wrongly conclude that the owner of the stone labeled image B was offering his goods at a much more favorable price.
Approaching the Pinnacle of Perfection, Small bumps in Quality Equal Big Bumps in Price.
In low quality commercial grade gemstones, small differences is quality will not make a great difference in price. However, as quality nears theoretical perfection the importance of smaller differences is magnified. In the stratosphere of gemstone quality, small differences can make for very large price differentials. Lets take an example that everyone knows, the D flawless diamond. I chose this example because diamonds are very precisely graded using an internationally accepted grading system. According to The Guide a well respected industry publication, the current wholesale price of a 1.00 carat D-IF is 31% higher than the very next color grade, E-IF, compared by clarity grade, (D-Fl vs D-VVS1) the spread is slightly less, about 29%. A similar comparison between diamonds with a color grade of L and O shows only a few hundred dollars separating the two grades. These differences will not show up in an online image.
In colored gemstones these same percentages apply and the grading equation becomes much more complex. Colorless diamonds are graded based on slight tonal variations of yellow. Color, any color, breaks down into two additional factors, hue and saturation which must be added to tone in the quality equation. In nature there are few pure hues. The hue of a gemstone is composed of primary, secondary and sometimes tertiary components, a top color ruby for example, may be 75% red, 15% purple and 10% orange. A blue sapphire with 10% (or less) green secondary hue which will likely not be visible in an online image will sell at a dramatically lower price than a stone with a pure or slightly purplish blue hue. Similarly, an emerald that is 75% green with a 10-15% secondary blue hue can sell for double the price of a slightly yellowish stone. These slight differences in hue do not show up even in professional images. This makes online comparison between two images very deceptive and of little or no value.
 Image B: The same gemstone after a tweak of the Saturation Enhancement tool in Photoshop The Value of Images:
Online images are of some value. As a professional, I never use images to determine which stones I will buy though sometimes they can identify a stone that I will not buy. It is usually possible to tell something about the clarity and cut of a given gem by viewing the image. Both come with caveats.
Online Images are Many Times the Size of The Stone; so are the inclusions:
The Mali garnet at left weighs approximately one carat. That means the stone is somewhere in the range of 6 mm in diameter. The image shown is 38mm, 6.33 times larger. Many gems that are eye-flawless will appear visibly included (flawed). In colored gemstones, the eye standard replaces the loupe standard, what the eye sees is what is important, magnification doesn’t effect price. In most varieties of colored gemstones, the difference between eye-clean and visibly included is dramatic. It is similar to the difference between a diamond graded flawless and another graded SI2.
In some cases the image will actually distort what the eye sees. Award winning gem photographer, Robert Weldon, makes the point that due to the limits of depth of field, the camera’s lens will compress inclusions into a single plane increasing the prominence of the inclusions in the image. This compression can lead to particular difficulties when trying to accurately render images of expensive type II and III gemstones such as emerald where the difference in value between an eye-clean gem and one with eye visible inclusions will be dramatic. Online images are normally in j.peg format. This format is created, Weldon points out, by subtracting information in the original high resolution image.
Images can be useful in evaluating cut but bear in mind that the visual performance in a gem depends upon lighting. A well lighted gemstone may appear to perform better than one that is less well lit. The lighting environment is not visible, multiple light sources of the type normally used in photography can mask real deficiencies in cut.
Color and Lighting:
In the good old days, there were two types of light; the sun and light from a natural flame, a fire or a candle. This, as I point out elsewhere, is the source of the legendary “ruby red” alexandrite. When that gem was discovered in the mid nineteenth century, incandescent light was supplied by a candle and candlelight is distinctly reddish—after the invention of the light bulb, the ruby red alexandrite became distinctly purple because that light source is yellowish. With today’s technology, it is possible to virtually cherry pick a lighting environment that is strong in a given color. You can light sapphires with blue light, rubies with red. Again the light source is not visible—so how would you know until your gem arrives in the mail.
Tags: gem images, gemstones images, online gem grading
Posted in Colored Stone grading system, Gemstone lighting, Online Images, collecting gems | 12 Comments »
April 23rd, 2011
 Gem quality tanzanite showing both its primary blue (left) and secondary purple (right) hues. Wise, Richard W., Secrets Of The Gem Trade, p.219 by Richard W. Wise, G.G.
©2011 (revised)
“Roses are red violets are blue but tanzanite ain’t violet.”
In 2007 The Tanzanite Foundation came out with a “standardized” grading system for tanzanite. Shortly later, The American Gem Trade Association’s laboratory adapted this grading system for use on its grading reports. All tanzanite would henceforth be graded on a color scale from violetish blue (vB) to bluish violet ( bV). Great idea, only one problem, they got the colors wrong, they missed purple.
Tanzanite’s primary hue is often blue but never a pure blue. Tanzanite exhibits a secondary hue which is always present. The secondary hue ranges from violet to purple, which though often confused in common speech are distinctly and definably different hues. Violet is a primary spectral hue that lies halfway between purple and blue and Purple is a secondary or modified spectral hue meaning that it results from a mixture of two primary spectral hues (red and blue). That explains why it doesn’t show up when you view the rainbow. Purple is positioned halfway between blue and red. The confusion of violet and purple is not new it goes a long way back but lets begin with Newton. Sir Isac is rightly given credit for initial work in color theory— published in 1706, his was the first color wheel.
 The original color wheel courtesy of Sir Isac Newton. In 1708 a Frenchman, Claude Boutet (Traité de la peinture en mignature) added purple. If you squint (image right) you will see that Newton identified indigo and violet as the two hues existing between blue and red. He either forgot purple or was perhaps pre-purple. Prior to the movement to standardize nomenclature in the 18th Century, colour names, like spelling, were not standardized. Tavernier, for example described the great blue diamond that he sold to Louis XIV as “violet.”
What isn’t generally understood as that Newton’s color wheel was all about opaque colors. Colored light adds a whole new dimension to the color equation.
Using oil paints, mix equal amounts of the two opaque colors red and blue together and the color you get is magenta. Purple can be mixed but painters are reluctant to use the term, preferring blue-violet instead, further adding to the confusion.
“Roses are red, violets are purple sugar is sweet and so is maple surple”
Roger Miller
Change from opaque media to to colored light you dramatically change the result. Mix equal amounts of red and blue light together and you get, guess what, purple.
After tanzanite has been heated, and virtually all tanzanite is heat treated, it is dichroic. That means that light entering the gem crystal divides into two rays each containing a portion of the visible spectrum. The dichroic colors of tanzanite are red and blue—the red is often reddish purple. If the gem is properly oriented before cutting, the face up color will mix the two yielding a range of hues from violetish blue (vB), to purplish blue (pB), to purple-blue (PB) to bluish purple (bP).
Where is the Lab Harmonizing Committee When You Really Need Them?
Studies show that it is particularly difficult for the human eye to distinguish purple, particularly at light tonal levels. This is known as the Bezold-Brücke effect. When purple is present in light-toned gems, the eye wants to see blue. In fact at light tones and low levels of saturation it is difficult to separate purple from violet or even pink. This occurs a lot in light toned topaz. Dealers will often categorize light purple as pink topaz. At darker tonal levels the eye is not bothered by the Bezold-Brücke effect. Yes tanzanite can often be violetish, even blue-violet, but finer stones are purplish-blue so how can purple be left out of the definition?
Traditionally tanzanite has been graded by what I call the “look-alike” standard. When the stone was first discovered, Harry Platt, the Vice President of Tiffanys compared it to sapphire. Platt declared that the finest color of tanzanite was a pure sapphire blue, which means that the finest tanzanite, like sapphire is a medium dark tone (75-80%) slightly violet to purplish blue. A medium dark toned true blue barely exists in nature and only in tanzanite when viewed in noon daylight or daylight fluorescent lighting. Put a “pure” blue tanzanite under the light bulb and a distinct violet to purple secondary hue will always be visible. In the finest stones, a medium dark toned purple adds a velvety richness to the blue, so beautiful that even the folks all the way over at the Tanzanite Foundation, at AGTA and even at GIA should be able to see it.
Tags: colors of gems, colours gems, Grading gemstones, Tanzanite
Posted in Tanzanite, gem value | 10 Comments »
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