Hill's Kashmir Sapphire

Posted by KurtS
April 18, 2009 at 2:42 am
Hmm…whether or not a particular stone can be scientifically proven as “Kashmir”, high-quality blue sapphires whose provenance links back to Kashmir enjoy a significant premium. To suggest that “Kashmir” is only a standard of color/quality for stones of any origin betrays a simple truth: the location itself has legendary status. Therefore invoking that legend upon a Burmese or Sri Lankan stone might be done to get more money, but it pays little respect to the sapphire’s true origin.

Posted by Haji Abdul Majid Butt GEOSCIENTIST
March 12, 2010 at 9:53 pm
For some 50 million years the Indian plate moved against the Eurasian plate, grinding, colliding & sliding, throwing up the Himalayas as a result.The pressure & temperature was immense with orogenic movement between 45-5ma under metamorphic environment formed Kashmir Sapphire; within the pegmatite bands traversing Actinolite-Tremolite schist.Kaolinisation treasured the most famous bluish crystal with intense corn flower blue color saturation with homogeneous spread with evenly distributed silk.Some call it geological art & for some it is a heritage like Picasso painting.Zoning is essential in Kashmir sapphire.Inclusions reveal stream & cloud geographical pattern of Padder area of Kashmir.Out of thousands of corrundum pieces only one qualifies the set parameter of Kashmir Sapphire hence the price is high.

Posted by - Lareef A. Samad - Administrator
August 8, 2012 at 5:56 am
Its a great privilege and honor to have a world renowned Geo-Scientist in the person of Haji Abdul Majid Butt, taking part and commenting on our webpage on the Hill's Kashmir Sapphire. Thank you, Sir, for your valuable comments on the origin, geology and unique characteristics of the famous cornflower blue Kashmir sapphire, the unofficial standard by which sapphires form other regions of the world are compared and evaluated, just as much as the "Golconda" diamond is the unofficial standard for comparing absolutely colorless, top-color or D-color diamonds originating from other regions of the world. I hope Dr. Haji Abdul Majid Butt's comments would to some extent clarify the doubts and reservations expressed by Setillia on January 2, 2009, about the positive identification of a sapphire's origin, particularly the Kashmir sapphire.
In his account Dr. Butt has summarized the salient features of Kashmir sapphires that may help to distinguish them from sapphires originating from other sources. These features are :-
1) The presence of an intense cornflower blue (velvet-blue) color, which in the GIA Sapphire color-grading system is awarded a perfect "10" quality rating, equivalent to a violet-blue hue, a medium-dark tone corresponding to "6" in the 9-level tone-grading and "vivid" color saturation level corresponding to "6," the maximum in the 6-level color-saturation grading.
2) The color appears to be spread homogeneously, even though microscopic examination shows distinct color zoning, a characteristic feature of Kashmir sapphires.
3) The presence of evenly distributed silk, which are fine rutile fibers that impart the slight milky or velvety color to the blue sapphires.
4) Inclusions found in Kashmir blue sapphires, visible either to the naked eye or under low magnification of the microscope, appear as clouds, feathers, veils and silk and may form a fingerprint impression that may be used to identify Kashmir sapphires. These inclusions include green mica, tourmaline, fine rutile and rarely zircon, pargasite, uranium etc.
5) Kashmir blue sapphire rough stones are usually embedded in a distinctive Kaolin clay-like matrix, exclusively found in Kashmir sapphires. A matrix that help preserve the sapphires for millions of years, and penetrates the surface of many stones.
The following thumbnails depict some of the inclusions discussed above. Please visit the website www.kashmirblue.com for more photographs of Kashmir blue sapphires with diagnostic inclusions.
1) Cloud-like appearance of silk in some Kashmir sapphires.
2) Fingerprint type of veil in Kashmir sapphires.
3) Hexagonal color-zoning with alternative blue and white color zones caused by rutile-silk. Photograph - Richard W. Hughes from his book Ruby & Sapphire
4) Silk resembling snowflake in Kashmir sapphires.
5) Swiss-cheese type of veil in some Kashmir sapphires.

What are the characteristics of Sri Lankan sapphires? Is there a possibility of some of these characters overlapping with those of Kashmir sapphires?

In terms of market ranking Sri Lankan sapphires rank third after the Kashmir and Mogok sapphires. This does not mean that Sri Lankan sapphires are in any way inferior to sapphires from the other two sources. In fact top quality Sri Lankan sapphires can equate or sometimes surpass the beauty of the other two.
The characteristics of Sri Lankan blue sapphires are :-
1) Sri Lankan blue sapphires can have every possible shade of blue, varying from delicate sky blue colors to rich saturated hues. However, they are generally lighter and brighter than the Kashmir and Burmese sapphires, and possess a saturated medium blue color that does not normally need enhancement by heating. Some areas of Sri Lanka (Rakwana and Elahera) also produce the famous corn-flower blue sapphires so characteristic of the famous and elusive Kashmir blue sapphires.These sapphires have the unique velvety blue color of the Kashmir sapphires.
2) The degree of transparency and clarity of Sri Lankan sapphires are excellent, and due to this the color of the stones appear to be spread homogeneously, even though closer microscopic examination shows distinct color zoning, with alternate colored and colorless bands as in Kashmir sapphires. One of the best examples of a Sri Lankan sapphire with a high degree of transparency and clarity is the 422.99-carat, rich deep blue, internally flawless, cushion-cut Logan Blue Sapphire, which is perhaps the second largest faceted blue sapphire in the world.
3) Rutile fibres known as silk are either evenly distributed, laid down in a hexagonal pattern alternating with colored zones, or laid down in patches forming cloud-like and other irregular patterns as in Kashmir sapphires.
4) Apart from rutile fibres other common solid inclusions found in Sri Lankan sapphires are zircon which form zircon halos or round-shaped or needle-lile crystals, rounded or dark prisms of rutile, hexagonal prisms of apatite, spinel octahedra, cube-shaped black uraninite crystals and needle-like or tabular crystals of diaspore.
5) Common liquid and gaseous inclusions include both liquid and gaseous carbon dioxide, forming feathers and fingerprints, which are healing patterns produced by the healing of fractures over a long period of time.
6) Negative crystals which are primary cavities formed during the rapid growth of the sapphire crystal and which may be filled partially or totally with liquid/gas (single-phase), or liquid/gas + solid (two-phase) or liquid + gas + solid (three-phase) inclusions, are quite common in Sri Lankan and Madagascar sapphires but less common in sapphires from other sources.
The following thumbnails depict :-
1) Rutile silk laid down in hexagonal pattern in a Sri Lankan sapphire - Photograph - Richard W. Hughes from his book Ruby & Sapphire
2) Zircon crystals found in blue sapphires of different origins.
3) Spinel octahedra from Sri Lanakn blue sapphires. Photograph - Richard W. Hughes from his book Ruby & Sapphire
4) Cube-shaped black Uraninite crystals from Sri Lankan sapphires.
5) Inclusions that look like zircon from Sri Lankan sapphires. Photograph - Richard W. Hughes from his book Ruby & Sapphire
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With regards to gemlite's next question as to the possibility of some of the characteristics of Sri Lankan sapphires overlapping with that of Kashmir sapphires, the answer is in the affirmative. The following facts will serve to drive home this point most effectively:-
Sri Lankan blue sapphires come in all possible shades of blue color. However, at least in some areas of Sri Lanka such as Elahera and Rakwana the blue sapphires produced have the unique velvety blue color, known as cornflower blue color, so characteristic of the famous Kashmir blue sapphires. The external and internal characteristics of the two blue sapphires are so identical that even reputed gem testing laboratories in the world had mistakenly testified the Elahera and Rakwana blue sapphires as of Kashmiri origin.
This is a clear-cut case of characteristics of sapphires, both external as well as internal, from two different sources, Sri Lanka and Kashmir, overlapping one another. Even Richard W. Hughes, the world renowned gemologist and author of the book "Ruby & Sapphire" the most authoritative book available on a single gem species - Corundum - refers to this mis-identification in his book, under the subheading "Original Sin." This is what the renowned author and gemologist has to say about this :-

Original sin
First, let me say that there is a definite market ranking for sapphire according to origin. It unfolds as follows:

1. Kashmir
2. Burma
3. Ceylon (Sri Lanka)
4. Everything else

That said, I would like to be allowed to burst all your bubbles. Origin is not what’s important – quality is.
Permit me to relate the following story. A number of years ago, a pit was discovered near Elahera on the Island of Gems – Sri Lanka. The stones from this mine bore such a resemblance to those of Kashmir that many labs actually issued papers certifying Kashmir as the source.
Some of the internal characteristics of Sri Lankan and Kashmir sapphires that overlap with each other are as follows :-
1) The presence of distinct color zoning in both sapphires.
2) Inclusions such as clouds, feathers, veils, silk, needle-like inclusions, fingerprints etc are common to both sapphires.
3) The nature and composition of inclusions, such as fine rutile fibers, zircon, uraninite, are common to both sapphires, but some inclusions like zircon, are more prevalent in Sri Lankan sapphires than in Kashmir sapphires.
4) Common liquid and gaseous inclusions, such as liquid and gaseous carbon dioxide that form healing patterns such as feathers and fingerprints.
5)Negative crystals are quite common in Sri Lankan sapphires but less common in Kashmir sapphires.

What characters are unique to Sri Lankan and Kashmir sapphires?

Some characteristics of Kashmir sapphires are found in most sapphires of Kashmiri origin, but are not unique to Kashmir sapphires as they are sometimes found in some sapphires of Sri Lankan and Burmese origins. Here there is an overlap of characteristics only for some sapphires of Sri Lanka and Burma sapphires, i.e. the overlap is partial. Eg. Presence of the intense cornflower blue color, a velvet-blue color caused by the presence of silk.
Some characteristics of Kashmir sapphires are found generally in most Kashmir sapphires and are also found generally in most Sri Lanka sapphires. Here the overlap is complete. Eg. Presence of distinct color-zoning generally in both Kashmir and Sri Lanka sapphires, and the presence of inclusions such as clouds, feathers, veils, silk, needle-like inclusions, fingerprints etc. which are common to both sapphires.
Likewise, there are some characteristics of Kashmir sapphires that are rare, found only in some Kashmir sapphires but yet unique as they are found only in Kashmir sapphires. Here there is no overlap of characters, as they are restricted to Kashmir sapphires only. Eg. Presence of pargasite needles, exclusively seen in less than 5% of Kashmir sapphires.
There are also characteristics of Kashmir sapphires that are not so rare, found only in Kashmir sapphires and are therefore unique. Here also there is no overlap of characters. Eg. Presence of inclusions such as green mica and tourmaline.
Some of the characteristics that are more prevalent in Sri Lankan sapphires than Kashmir sapphires include the presence of zircon halos, and rounded or needle-like crystals of zircon; the presence of negative crystals. The overlap of characters in this case is partial.
However, the presence of inclusions such as spinel octahedra, hexagonal prisms of apatite and needle-like or tabular crystals of diaspore, may be indicative of Sri Lanka sapphires, as they are unique and probably found only in sapphires of Sri Lankan origin.

Thanks for your detailed reply. However, I would like to know whether identifying the nature of inclusions is the only criteria used in determining the country of origin of a sapphire.

Identification of inclusions is the first criterion used by gemologists in determining the country of origin of a blue sapphire. As pointed out earlier, the presence of inclusions that are unique to certain sapphire producing regions, can be easily used in identifying the source, eg. the presence of needle-like pargasite or tourmaline crystals, would without any doubt indicate Kashmiri origin of the sapphire and the presence of uranpyrochlore inclusions would indicate Cambodian or southern Vietnam origin.
Apart from inclusions gemologists also use other criteria in determining the possible source of a sapphire. These include the use of optical properties, growth characteristics and chemical composition.
An optical property that imparts a soft velvety appearance to blue sapphires caused by the presence of silk, might indicate a Kashmiri origin, prompting the gemologists to look for other conclusive evidences for Kashmiri origin. Fluorescence is another optical property that may provide a clue to the origin of a gem. Sapphires originating from most of the world's sources are inert to long and short wave ultraviolet light except Sri Lankan sapphires that fluoresce regularly in U-V light. The presence of fluorescence is one indication of the sapphires origin, although not all Sri Lankan stones fluoresce.
Growth characteristics such as the way crystals grow in a deposit can also provide clues to a sapphire's origin. Growth patterns as observed under a microscope can be diagnostic, eg.tight optical growth patterns are found regularly in Madagascan sapphires, less regularly in Sri Lankan and Myanmar stones, and not at all in Kashmir sapphires. Likewise color-zoning in sapphires can also give an indication as to their origin. Eg.Sapphire crystals from Antsiranana Province in Madagascar often display blueviolet, greenish blue, and greenish yellow zones within the same crystal. Color-zoning in Kashmir sapphires show distinct zones of alternating blue and milky-white.
Other useful tools that may be helpful in determining the country of origin of a sapphire are spectrophotometry and energy-dispersive X-ray fluorescence (EDXRF), that can unravel the chemical make-up of a sapphire by identifying the elements of which the sapphire is composed of and even detecting various trace elements found in and on the surface of the sapphire. Most sapphires would show the same basic composition, but different concentrations of trace elements that would give a clue from which deposit the sapphire originated. Eg. Some Cambodian sapphires are the exact look-alike of Kashmir sapphires and are often touted as Kashmir sapphires. However, spectrophotometric and EDXRF analysis show that Cambodian sapphires have very high concentrations of the trace element iron compared to Kashmir sapphires that typically have very low iron levels.

If as you said several criteria are available for determining the source of a sapphire, such as identification of inclusions, the use of optical properties, growth characteristics and determination of chemical composition, why is it that renowned gem testing laboratories like the GIA do not issue origin reports on any gemstones including sapphires?

Gemstone geographic origin determination is a science that is still in its infancy and not yet fully developed, despite the advances in science and technology and the availability of modern tools and equipment for gathering relevant information, such as the Ultra Violet-Visible-Near Infrared spectrometer (UV-ViS-NIR) , the Raman spectroscope, Photo-Acoustic Spectroscopy (PAS), Fourier Transform Infrared Spectrometer (FT-IR), Energy-dispersive X-ray Fluorescence (ED-XRF), Laser-induced Breakdown Spectroscope (LIBS), Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS), and the Scanning Electron Microscope (SEM). The geographic origin of a given sapphire is determined by collecting all relevant data on the sapphire, such as the nature of the inclusions, optical properties, growth characteristics if any, the nature and concentration of trace elements etc. and comparing it with the properties of a reference sapphire collection, in a database maintained by the Laboratory, containing a sufficiently high number of samples from commercially relevant mining areas and deposits worldwide which include reference stones from exhausted mines or deposits where production has ceased.
Such an approach will be in order, as long as the given sapphire comes from an established mine whose existence is known and from which samples had been collected previously for the reference database. However, problems can arise when the given sapphire originates from a new deposit, from a previously unknown mine, from which geologists have not had the opportunity to collect samples. In such cases there have been instances when two different laboratories have issued widely differing geographic origin reports for the same sapphire, or a sapphire had been assigned a geographic origin that has a direct bearing on its market value, such as the blue sapphires from Elahera, Sri Lanka, misidentified as Kashmir blue sapphires, when the deposit was first discovered.
Mis-identification of the origin of a gemstone appears to be the unfortunate consequence of the lack of funding and research, in updating the reference database maintained by gem-testing laboratories, by visiting and collecting samples and relevant geological information from new deposits and mines, as well as new samples from traditional sources, such as Burma and Sri Lanka. However, given the fact that new sources and deposits are being discovered around the world on a regular basis, investigating the physical, chemical, optical, and other properties such as inclusion characteristics, of the new material collected, and updating the reference database maintained by the laboratory might prove to be a very difficult and challenging task.
Sapphires and Rubies,which are varieties of the mineral Corundum (Aluminium oxide), can have two broad geological origins - Basaltic or magmatic and non-basaltic or metamorphic. Blue sapphire deposits from Australia, Cambodia, Thailand, China (Shandong), Rwanda etc. are basaltic in origin, and those from Kashmir, Burma, Sri Lanka, Madagascar and Tanzania are non-basaltic or metamorphic. Most laboratories can easily distinguish between a sapphire of basaltic origin and non-basaltic origin. However, after establishing the geological origin of the sapphire, difficulties arise when trying to distinguish between deposits of identical geological origin, eg. between Kashmir, Burma and Sri Lanka sapphires, or between Madagascar, Tanzania and Sri Lanka sapphires all of non-basaltic origin, or between Australia, Cambodia and Thailand sapphires of basaltic origin. Such difficulties arise mainly because of the partial or total overlap of characteristics between sapphires of identical geological origin, discussed previously. Where the character is unique, without any overlap identification is simple and straightforward, eg. presence of pargasite or tourmaline crystals unique only to some Kashmir sapphires,and the presence of uranpyrochlore inclusions unique only to Cambodian and Vietnam sapphires.
Where most of the characters are similar and overlapping as in some Sri Lankan and Kashmir sapphires or Sri Lankan and Madagascar sapphires, without a unique diagnostic character, a comprehensive approach is applied, such as identification and description of inclusions, analysis of chemical composition and trace elements, and spectral properties. The evaluation and interpretation of the observed features, combined with additional advanced analysis, may allow a laboratory to reach a conclusion on the geographic origin of the gemstones. Advanced analysis used to distinguish between Sri Lankan and Madagascar sapphires by the Gemological Association of All Japan (GAAJ) is LA-ICP-MS analysis, which showed that minute amount of heavy elements such as Sn (tin) and Ta (tantalum) were under detection limit in the stones from Sri Lanka, while several to several dozens ppm of those elements were detected in the stones from Madagascar, a significant difference that can be used to distinguish between the two.
However, despite advances in analytical methods only a success rate of around 80% has been achieved in the relatively new field of Geographic Origin Determination, according to C. R. "Cap" Beesley of the American Gemological Laboratories (AGL) of New York. AGL maintains one of the largest reference databases in the world, consisting data of over 10,000 samples collected from gem mines and deposits situated around the world. Factors that can complicate Geographic Origin Determination are :- 1) Heat treatment that can alter the chemistry of gemstones (Eg. the distinctive color zoning seen in sapphires from Andranondambo, Madagascar, becomes significantly less distinct when the stones are heated); 2) Non-uniformity of characteristics of sapphires even from different areas of the same deposit 3) Discovery of new locations bringing hitherto unknown new materials into the market; 4) the need to maintain a sample of stones that remains current. eg. data collected from one of the best sample populations of Ceylon blue sapphires 20 years ago may not be valid today, and has to be continuously updated from time to time.
Inspite of all the difficulties, some of the renowned laboratories that issue Geographic-origin/Country-of-origin reports on sapphires are the American Gemological Laboratories (AGL), Gubelin Gem Lab (GGL), Swiss Gemmological Institute (SSEF), and the American Gem Trade Association (AGTA) Gemological Testing Center. However, these labs concentrate mainly on sapphires originating from non-basaltic deposits, such as Kashmir, Burma, Sri Lanka, Madagascar, Tanzania etc. whose sapphires command premium prices at international markets and not on sapphires originating from basaltic deposits, such as Rwanda, Australia, Cambodia, Thailand, Shandong [China], etc., where it is of little commercial interest to know the locality.
Since Geographic/Country-of-origin of a gemstone is based more on expert opinion than on conclusive evidence, there is a tendency for labs to differ occasionally, when issuing reports on the same sapphire. Sometimes when too many ambiguities arise, the labs may issue a tentative opinion or no opinion at all. All these difficulties come within the failure rate or negative identification of 20%.
A failure rate of 20% is considered too high and unacceptable by many renowned laboratories such as the Gemological Institute of America (GIA) and Professional Gem Sciences (PGSL) Inc. founded by Thomas and Myriam Tashey. Hence, such labs do not issue Geographic/Country-of-origin reports on any gemstone.

Further Comments on Kashmir Sapphires by Haji Abdul Majid Butt, Geoscientist.

Haji Abdul Majid Butt, GEOSCIENTIST

June 29, 2013 at 2:33 pm I AM IN LONDON UP TO 3RD WEEK of JULY 13. ARE YOU INTERESTED IN THE UPDATE OF KASHMIR SAPPHIRES UNTIL 2013 ?

Haji Abdul Majid Butt, GEOSCIENTIST

July 2, 2013 at 1:16 pm In 2010 one run of mine sapphire crystal was recovered by JK Minerals weighing 63.60 gm estimated at Rs.5 crores.
In mid May 2013 a rare 19.88 carat "Star of Kashmir" was auctioned by Christie's at 3.5 million US dollars, smashing all previous records.
Year/ Production /Sale Revenue from JK Minerals:-
2008 – 16,000 gm /130.00 lakhs in Rupees.
2009 - 12,330 gm / Rs.74.70 lakhs
2010 - 4502 gm – Rs.
2011 - 8820 gm, 5799 gm / RS 82.29 lakhs
2012 - 4520 gm, 4281gm / Rs 43.28lakhs
2013 – – / Rs 50.00lakhs

Pl. do incorporate the above info as update till July 2013.

At the Christie's Magnificent Jewels Sale 1397, held in Geneva on May 15, 2013, "The Star of Kashmir Sapphire" featured as Lot No. 247 and was described as THE STAR OF KASHMIR - AN EXCEPTIONAL SAPPHIRE AND DIAMOND RING. A pre-sale estimate of CHF 2.4-2.9 million (USD 2.53-3.05 million) was placed on the lot described as a rare and exceptional treasure. The 19.88-carat, cushion-shaped sapphire was set as the centerpiece of a platinum ring, flanked on either side with cushion-shaped diamonds, weighing approximately 2.72 and 3.02 carats.
The Lot was accompanied by three lab reports issued by SSEF (Swiss Gemological Institute), GGL (Gubelin Gem Lab) and AGL (American Gemological Laboratories) testifying to the effect that the blue sapphire is a natural sapphire of Kashmiri origin, with no evidence of heating or clarity enhancement, and such natural Kashmiri sapphires of this size and purity are extremely rare and exceptional treasures of nature.
The Star of Kashmir Sapphire ring eventually sold for a whopping US$ 3,484,102 equivalent to 20 Crores of Indian rupees, a new world record price for price per carat and whole stone, ever paid for a blue sapphire, pushing the 22.66-carat Hill's Kashmir Sapphire that sold for US$ 3,064,000 to second place and the 62.02-carat Rockefeller Sapphire that sold for US$ 3,031,000 to third place.
Commenting on the sale, Christie's said "The Star of Kashmir is part of the exclusive family of the rarest Kashmir sapphires ever to be offered at auction. This superb gemstone combines an exceptional size with a richly saturated and homogenous cornflower blue color that is highly desired in Kashmir gems"