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 | 9 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 | 9 Comments »
February 25th, 2011
by Richard W. Wise, G.G.
©2011
 Three black opals showing two tones of body color. The Australian valuing system recognizes nine degrees of body tone. The gems at right would be graded N1, the oval to the left N3. Photo: Cody Opal Over the past decade it has been my privilege to get up close and personal with some of the world’s most fabulous opals. My love affair with this idiosyncratic gem began in 1991 with a visit to the opal fields of Queensland. At that time I was researching an article that would eventually be featured in Gems & Gemology, the journal of the Gemological Institute of America, under the title: Queensland Boulder Opal.
Queensland, like most of the Australian outback, has come to embody the frontier spirit, the ethos of America’s old west. Strong solitary loners, men of few words with names like Texas Jack and Silk Shirt Joe, labored under almost unbelievably harsh conditions, nourished by the stubborn belief that sooner or later they would hit pay dirt. It took just a few days days with the guidance of the late Vince Evert to realize that even in the waning days of the 20th Century, much of that spirit lived on.
With Evert as our guide, the adventure began when our Piper Apache approached a bumpy dirt airstrip that had been carved out of the arid plains on the outskirts of Winton (marked w/red dot), a frontier town 350 miles into the Queensland outback. The Evert family are among the town’s most substantial citizens. Proprietors of a gift shop and the town’s only outdoor theater, they are also one of the area’s largest mining operations–entrepreneurs and opal cutters. It was Vince, dressed in khaki with a plain brimmed Akubra hat—Australia’s five gallon version of the ten gallon hat—who stood waiting as our single engine plane taxied to a dusty stop.
It was a sunny day in early March, the temperature hovered around 120°F. The outback is basically desert, and water is drawn from bore holes, wells that reach as much as 3,000 feet down below the cracked brown earth; the water comes up hot and stinking of sulfur.
Describing Opal:
Opal nomenclature can be a bit tricky. In the old days unwieldy and confusing terms such as white, crystal, semi-black, semi-black crystal and black were used. The new Australian system of classification now recognizes nine levels of body color or body tone (N1-N9).
 Figure 1: Opal body tones, there are nine basic grades and opal gets noticeable lighter in body color as you go down the scale. Photo: Cody Opal Body color is the background color, the color of that part of the opal which shows no chromatic fire (play of color). Opal classifications are based strictly on visual appearance. Black opal, generally speaking, is found at Lightning Ridge, but all opals produced at The Ridge are not described as black. This differs from the system of pearl classification where, for example, any pearl produced by the Pinctada Margaritifera (black lip) oyster, regardless of body tone, is termed a black pearl.
Grading Opal:
“You can learn diamond grading in an afternoon, learning to grade opal might take twenty-five years.”
Richard T. Liddicoat
In my book, Secrets Of The Gem Trade, The Connoisseur’s Guide…, I devote considerable space to a comprehensive discussion of the grading of opal, thus I will not attempt to cover all bases in this post. The descriptive system cited above was not in use at the time the book was published (2003).
 Figure 2: Saturation levels in opal. Viewed from left to right the stones show higher levels of saturation (brightness). Be careful of the last one on the right as it depicts a pattern of large flashes which will appear brighter than the smaller more discrete pinfire play-of-color in the images to the left. Photo: Cody Opal Opal is like a light bulb–the brighter, the better. It is not the given hue, but the brightness or saturation of hue that is the primary criterion of value. Color, as we know, divides into three components: hue, saturation and tone. Hue is color as the term is ordinarily used, e.g. greenish blue, pinkish purple. Saturation refers to the quantity, or brightness of a given hue. Figure 2 depicts levels of saturation, although some opal experts prefer the term brilliance. Moving from left to right, the colors become more intense. As opal types, the first two stones in figure 2 would be classified N1, the third N2 and the fourth probably N3. N1-N4 are examples of what is normally called black opal. N6-N7 are called crystal opal and N8-N9 are light opal.
 A black opal exhibiting the rare "peacock's tail" pattern. The opal was cut in a shape that resembled a butterfly's wing. At the risk of mixing metaphors, we designed and created an opal butterfly with a peacock pattern in 18k yellow, rose and white gold. The design rendering is shown as background. Courtesy: R. W. Wise, Goldsmiths. Photo: Jeff Scovil Patterns:
Pattern is important. Larger blocks of color are more highly desired than smaller. Figure 2: Moving from left to right the color becomes increasingly more saturated. Note also that the stone at the far right is more beautiful because the color is not only more saturated (brighter), but also because the pattern of larger chunks of color is both more visible and more pleasing to the eye. The grading of patterns is unique to opal. Some, like peacock’s tail, are easily identified because they closely resemble their pattern-name. There is a hierarchy of rarity associated with pattern that any true opalholic must learn by rote.
Generally speaking, those evocative patterns which are readily identifiable with names like Grass, Chinese Writing and Mackerel Sky are the most desired. At the very top of the list sits Harlequin, rarest of the rare. This pattern is named for the ambiguous clown-like figures dressed in suits with large diamond shaped patches which inhabit the paintings of Picasso’s Blue period (see below left). I have seen only three harlequins in twenty years and only two with a true red component.
 Millennium, a 25 carat Harlequin opal sold several years ago by R. W. Wise, Goldsmiths. Millennium is known as a red multicolor because the gem has the the double virtues of large angular blocks of color and a dominant red, which is the rarest hue in opal. Photo: Rudy Weber Pricing Opal:
Opal prices can vary from a few dollars to hundreds of thousands. Additional criteria including color and transparency are also key to the valuing equation. Beauty is, as always, the defining criterion.
In 2008, opal experts Andrew and Damien Cody published a beautiful booklet, The Opal Story, A Guidebook (ISBN: 978-0-9805987). Aside from some of the most magnificent photographs of some of the finest opals ever to see the light of day, the Codys identify seven value factors in the grading of opal: type, brilliance, body tone, transparency, pattern, dominant diffracted colors, thickness of color bar and shape.  These criteria are consistent with the new Australian system of valuing. I would advise anyone seeking to sharpen their understanding of opal grading to purchase a copy of this booklet. The Opal Story Book and DVD is available for $29.95 AUD plus shipping and handling of $6 AUD. Orders can be emailed to opal@codyopal.com . The order should include mailing address and phone number together with credit card details.
Tags: appraising opal, Black Opal, Queensland Boulder Opal, valuing opal
Posted in Appraising and valuing Opal, Black Opal, Crystal Opal, Lightning Ridge, Opal, Queensland Boulder Opal | 3 Comments »
February 14th, 2011
by Richard W. Wise G.G.
©2011
Tucson Gem Shows; A Brief Roundup:
Early Saturday morning, Rebekah and I woke from a deep sleep and reluctantly dragged ourselves to the Tucson International Airport. Our two weeks at the annual gem-orgy was over, goodbye blue skies, hello ice and snow. The Berkshires may look “dreamlike on account of that frosting” (James Taylor) but we are, quite frankly, over it! The icicles on our roof are four feet long!
Tucson was quite productive this year. The recession appears to be on the wane. Attendance was up and most vendors were quite pleased, with sales as much as 50% above last year’s—though in some cases, that’s not saying much! Prices in most gem varieties were strong with vendors unwilling to discount. Big auction prices realized by exceptional rubies and sapphires appear to be putting some upward pressure on smaller, finer goods.
Book Review: Terra Spinel:
Yavorskyy, Vladyslav and Hughes, Richard W., Terra Spinel, 2010 Privately Published and Printed in Hong Kong. Full Color, 200 pages; 240 x 260 mm ISBN: 978-0-615-40901-6
Though this is hardly news, in the past three years, spinel prices have doubled, particularly for finer qualities of red, pink and Cobalt blue varieties. Spinel has a long and illustrious history in the gem world, but it languished and traded in an indifferent market through most of the past century. Perhaps this is due to the fact that colorless spinel was used as a diamond substitute in the 19th Century and the bad odor of “simulant” clung to the stone for much of the 20th. This also explains why there has never been a comprehensive book written on spinel. For those looking for such a volume, Terra Spinel is not it.
 A magnificent red spinel before and after Terra Spinel, a large format coffee table sized portfolio (9.75 x 10.25″), designed, edited and written with the help of Richard W. Hughes, author of the seminal Ruby & Sapphire, is a picture book, but what pictures! Both Hughes and Yavorskyy are great photographers. My wife and I look forward each year to receiving Yavorskyy’s annual photo-calendar (not available this year due to the cost of producing the book). Vlad’s photographs burrow down and capture the gritty, often humorous and at times profound everyday realities of the remote regions he visits in search of gemstones. Like the dustjacket pictured above, the book is printed on a medium-dark gray background which makes the images really pop.
 Old man, a villager from remote Afghanistan, by Yavorskyy Beginning with the magnificent 110 carat polished red spinel rough pictured on the cover, the book chronicles some of the fine gemstones Yavorskyy has sourced over the years. Each page, even those with full page images of mines, villages and temples, and these are the majority, includes an example of a beautiful gemstone often juxtaposing rough and polished images of the same gem. Most of these images are labeled with the weight, at least, of the cut version, but many are not. Unfortunately this is also true of the final section entitled Spinel by the Book, which is essentially a seven page thumbnail sketch of the entire collection. Given its importance, a list of sizes would have been very useful.
Hughes does begin with a brief but informative history of both the gem and its ancient names– spinel, balas ruby and lal. Brief biographies and large images of three of the world’s most famous spinels; Timur’s, The Black Prince’s and Catherine the Great’s rubies, are also provided. Having recently visited the Imperial Collections in Moscow and St. Petersburg (October), I can attest to the fact that the color renderings of these important gems are the best available. There are full color maps of both the major historical and current mining areas. The book also contains a helpful two page bibliography.
Terra Spinel is a beautifully designed and sumptuously produced hardcover. The book is swathed in black cloth and wrapped in a thick chrome-coat dustjacket. The title and authors’ names and blind stamped in embossed silver on both front cover and spine. A color panorama begins on the inside front cover (endpaper) and extends to the endsheet; ditto inside the back cover. These are all expensive extras which more than justify its $95.00 price. Unfortunately shipping from Bangkok will cost another $65.00 bringing the total to $160.00. The book may be ordered directly from the website. For those traveling, the book will be available at the Hong Kong International Jewellery Show: 4–8 March 2011. Grand Hall, Booth G09; Baselworld: 24–31 March 2011. Booth C30, Hall 3.1.
Tags: book review, Richard W. Hughes, Spinel, Terra Spinel, Vladyslav Yavorskyy
Posted in Gem Books, Gem History, Russian Diamond Fund, Spinel | 4 Comments »
January 15th, 2011
by Richard W. Wise, G.G.
©2010
Of Dentists and Doughboys:
What is it about gemstones that gives buyers the idea that somewhere, somehow they can get something for nothing? Why are dentists particularly vulnerable? Over the course of my career I have spoken to not less than five members of that gullible fraternity who “invested” in gems. One salesman told my dentist that Japanese investors were eager to pay twice the price for low grade aquarium gravel contained in that little sealed packet. “Why didn’t you suggest that the salesman board a jet to Tokyo and reap those high profits”? I asked Dr. Pain. He shrugged, smiled sheepishly and looked down at his shoes.
Did you hear the one about the smart New York lawyer who, after I told him about a buying trip to Thailand and Burma, blithely asked, “Yeah, but do they know what they’ve got?” Well, yes Virgina, these folks have have been mining and marketing gems since the Bronze Age, I think it’s fair to say that they have finally figured it out.
A Potentially Explosive Investment:
I suppose the neophyte gem investor is really no different from the clueless homeowner who believed those friendly folks at Country-Wide when they told him he could support his lifestyle by the continued plundering of the equity in his home and is now so far underwater he can’t even draw breath through a snorkel—a fool and his money…I remember another occasion, a young couple, yoga students who had spent time in an ashram in India. They met an Indian fellow who’s father owned a ruby mine. Despite my warnings they returned to India and sunk $10,000 into dyed and oiled ruby bead made from low-grade East African rough that originally sold for $150.00 per kilo.
 Emerald Mine, Panjshir Valley, Afghanistan: Photo courtesy Vincent Pardieu More recently I was approached by two army officers currently serving in Afghanistan to appraise gemstones that they had bought for investment. One of the men, a lieutenant who seemed particularly eager to buy, told me he was a specialist in the very dangerous profession of mine clearance. I advised him to stop buying and volunteered to take a look at his purchases. After vetting his collection which included lead-glass filled ruby and low end tanzanite, I suggested that purchasing gems for investment on the open market in Afghanistan could very likely have a more explosive impact on his finances than his current day job.
Our service members should be aware that there appears to be an entire industry in Afghanistan, similar to the one that existed in Pattaya, Thailand during the Vietnam War, dedicated to fleecing members of the American military. According to Gary Bowersox, a gem dealer who travels frequently to Afghanistan and co-author of Gemstones of Afghanistan: “The Afghanistan market is flooded with treated and synthetic gems where uneducated Afghan gem dealers are selling volumes of gems to foreign soldiers who are also uneducated in gemology.”
Professional appraiser, Charlene Bradbury, G.G. has appraised 50-100 stones brought back by approximately ten servicemen from Afghanistan over the past two years. she notes that 90% were either synthetic with a fairly large proportion of lead glass filled rubies. Most others were low grade, lead glass filled rubies.
 Getting The Lead Out: (above)Lead glass filled ruby after heating that removed some of the glass. Below: Same ruby under magnification. Photo: Shane F. McClure
Our Responsibility:
I know that I promised more on the topic of Online Gem Evaluation and I will, but I really feel that my experience with the two army officers is a cautionary tale that needed to be told. Our boys in the military are doing a dirty and very dangerous job for us in Afghanistan and I believe that we, as members of the gem fraternity, have a responsibility to protect them in whatever small way we can.
Countdown To Tucson:
The annual free-for-all smorgasbord known collectively as the Tucson Gem Shows will begin at the end of this month. I have been attending the shows for over twenty-five years and have watched awestruck by the spectacular growth of this annual event. My wife and I spend two weeks and work every day and still find it impossible to take in all of the shows. As always, I enjoy the hunt. It can be frustrating but there is nothing more satisfying than the thrill of sourcing a particularly fine gem at an out of the way booth, tucked into some back alley show.
Posted in collecting gems, gem value, gemstone investment | 8 Comments »
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