GEMLAB REPORT:
May 1998 - Issue #11
By: Ted Themelis
themelis@ganoksin.com
In This Edition:
The country-of-origin in ruby & sapphire
http://www.ganoksin.com/borisat/nenam/gemlab11.htm
In the diamond industry, the origin of a diamond plays absolutely
no role in its marketability; however, in the colored stone market
the origin issue has raised considerable concerns and hot debates
over the years. Since the 1970’s, several well-known gemological
laboratories, responding to strong requests from the colored
gemstone market, have issued certificates of country-of-origin for
certain types of rubies and sapphires. Certificates identifying
gems of “superior” origin (i.e. Kashmir, Burma) are used in the
colored gemstone trade as an effective selling tool, to identify a
quality product, and add a premium to the price of these gems. The
impact of these certificates on the gemstone market has been
phenomenal. For example, if two rubies of equal color, quality, and
size, were submitted to an accredited gemological trade laboratory,
and one stone received a lab report identifying it as Burmese in
origin, and the other as African, the Burmese stone would sell for
a considerably higher price.
Not all rubies and sapphires originating from “superior”
localities are of fine quality, nor are they necessarily beautiful.
For instance, many low quality Burmese rubies may easily be
confused with rubies of different origin having virtually the same
appearance. These Burmese rubies, when accompanied by origin
certificates will be priced higher. There is no specific formula or
method, by which premiums are added to the value of the rubies and
sapphires accompanied by origin certificates. The law of supply and
demand determines the final price.
Different localities of similar geological environment do not
produce gems of equal quality. For instance, a Mogok-type
geological environment is very similar to certain areas in Tanzania
(Kisoli, Arusha Province). Although rubies are produced in both
localities, the Kisoli rubies are of lower quality when compared
with their Mogok counterparts. Until recently, gemological
laboratories were able to determine, with some reasonable degree of
certainty, the origin of some rubies and sapphires. Today, most
commercial quality sapphires and nearly all-commercial quality
rubies are heat-treated, resulting in some alteration of their key
diagnostic features. Recent advances in heating methods make
positive identification of the origin of rubies and sapphires more
difficult and in some cases impossible.
Origin certificates.
The country of origin certificates and gemological reports
attesting “no heat-status” on fine quality rubies and sapphires are
actually designations directed to high-end gem buyers who are
motivated to buy a rare Burmese ruby or a Kashmir blue sapphire. It
is no different than buying Colombian coffee beans or French
perfume. Some people want the best and are willing to pay for it.
Undoubtedly, recording and cataloging various inclusions and other
characteristic features by their origin is of paramount
importance, adding valuable scientific data to gemological
knowledge. Commercial origin reports have absolutely no scientific
value to the research gemologists, unless are accompanied by
detailed descriptions and explanations of the criteria used to
arrive at their conclusions. Commercial origin reports do not
necessarily guarantee high quality product, as many naively assume.
These origin reports are subjective documents, similar to documents
that accompany works of art, or antique objects, etc. For certain
class of gem collectors, origin reports are desirable and, in many
cases, necessary. Many gem connoisseurs admit that origin
certificates provide them with a certain psychological satisfaction
and assurance of a high-quality product.
Economics of heat-treated rubies & sapphires from “superior”
localities.
Regarding fine quality rubies and sapphires from “superior”
localities, which display certain undesirable appearance
characteristics, an interesting point of discussion arises, as the
following example illustrates:
A premium was added to a Burmese ruby (with an origin
certificate), characterized by silk inclusions. If this Burmese
ruby is successfully heated to reduce/remove the silk, its clarity
is enhanced and its value increases. Since this Burmese ruby is now
labeled as "heated’, some price reduction is expected. If the silk
was not removed from this Burmese ruby and fissures were developed
due to heating, its clarity grade would be reduced. Thus, the ruby
will have lost some of its value in quality (due to fissures), and
by its heat treatment status (if detected by the lab). Here is the
hot question:
What is the actual value of this stone?
Only the person who has studied the stone before and after the
heat treatment will be able to make the actual evaluation and
answer the question. The opinion of all other intermediate persons,
as well as the ultimate buyer varies widely. In any case, because
heat treatment is detected, it is expected that the stone will be
less valuable, even though is accompanied by a certificate of
origin.
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