The Gem Spectrum is Pala International’s
free newsletter. Edited by Pala’s own Gabrièl
Mattice, it is filled with interesting articles on various
aspects of gems.
distribute The Gem Spectrum free
within the United States to members
of the gem and jewelry trades. If
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We often receive phone calls from our clients asking well-thought
out questions. Since many of you have the same questions, we
decided to answer them through a newsletter. Welcome to our first
issue. We hope you’ll take time to read, enjoy and contact
us with any questions or information you feel would be interesting
to share with others in our field.
Within recent months, significant
quantities of top-quality peridot have appeared on the world
market. Sometime in the late spring of 1992 this find was
uncovered in Pakistan’s Suppatt region and is the focus
of this issue.
|Pakistan peridot crystal (Photo:
Harold & Erica Van Pelt)
magnetite-forming veins are the source of income to some
2,000 local Pakistani miners working several different mining
locations. The recovery method is an arduous task of drilling
and blasting (by hand) which has resulted in yields of several
thousand kilos. These numbers easily qualify this find as
a major contender to compete with the historical locations
of Burma and Arizona.
to the Burmese and Egyptian localities, which also produce
primary crystal formations, the Pakistani peridot forms in
pockets, in high temperature veins so the material is virtually
transparent. Peridot produced from porphyroblasts in basalts
(i.e. the Arizona variety) form more included crystals which
will usually display the more commonly known lilly pad and
black chromite inclusions. The Pakistani peridot shows inclusions
which have not yet been positively identified as of this printing,
however material has been submitted to the GIA for analysis.
Prices for smaller, more commercial sizes will have to compete
with the China and Arizona material but over 15-ct gems will
perhaps command a premium comparable to the finest Burmese
Pakistan, formerly a republic
in southern Asia, is bordered by India to the east, the Arabian
Sea (an arm of the Indian Ocean) to the south, Iran to the
southwest, and Afghanistan to the west and north. This region
became part of British India in 1857. When India gained its
independence in 1947, Moslem leaders demanded a separate Moslem
state, and the nation of Pakistan was established. Originally,
Pakistan consisted of two regions, West Pakistan (now Pakistan)
and East Pakistan (now Bangladesh).
This issue’s reading recommendation is Peter Bancroft’s Gem
and Crystal Treasures, published by Western Enterprises and the Mineralogical
Record. Dr. Bancroft, a distinguished writer and lecturer on
mining, minerals and gemstones has compiled a terrific hardcover,
475-plus page walk through time by bringing together 667 black-and-white
original mining pictures and illustrations, as well as 320 color
photos of crystals and gemstones. Touching upon some of the world’s
most prolific deposits, Peter Bancroft has uncovered a wide range
of information, some of it never before published. Gem and Crystal
Treasures is highly readable and will make a valuable addition
to anyone’s reference library. This book normally retails for
$60, however we have a limited number available at $37.50.
Suppatt region is nestled in the
highlands above the Indus River Valley
of the Himalayan Mountains and getting
there is no field trip. It is said
to take a seven-hour horseback ride
before the grueling two day hike
to the mining area can even begin.
According to Laura Thompson, President
of Shades of the Earth in
Arizona, travel is mostly dangerous
due to the high incidence of landslides.
Because of the ruggedness of the
terrain, not to mention the winter
snow deep enough to cover a large
house, mining is limited to only
a few months a year (late JuneSeptember).
is a magnesium-iron silicate, which in fine quality, contains
much more magnesium than iron. Since the proportions vary
in different deposits, some property variation is expected.
The refractive indices for the usual green or the rare brown
gem peridot is 1.6541.690 with a birefringence of (0.036).
Specific gravity (SG) is typically 3.32 to 3.35, but slightly
higher readings are occasionally encountered. Though its
properties are similar, peridot can be distinguished from
sinhalite both by its higher SG and by a beta index that
is always near the midpoint between alpha and gamma (Liddicoat
1989, Handbook of Gem Identification). Identification
should be able to be made with limited instrumentation.
I am fortunate in that we get to see and work on some
of the newest and most exotic material available. When
I first examined the peridot crystals from Pakistan,
I saw hidden inside these large, etched crystals, many
areas of clean, cuttable material. These crystals require
a lot of study before preforming because you want to
retrieve the biggest stones first, without sacrificing
the smaller ones. To isolate the clean areas, saw cuts
must follow the twisting veil inclusions. Once the
cuttable portion of the rough has been isolated, orientation
is less crucial than in some peridot. The yellow and
olive tones are not as prevalent from this location,
thus the rich green color can be achieved from almost
material is usually best fashioned with a mixed
cut (brilliant and step-cut). The step facets
serve two purposes, weight retention and color
enrichment, while the brilliant facets, located
especially in the culet and girdle areas, bring
the stone to life with more scintillation and
enhance the dispersion. These are the traits
of a well-cut peridot.
particular Pakistan location produces
peridot that is a cutter’s dream it
polishes easily, usually without the
graininess and crumbling typical of
peridot from other locations.
this peridot from Pakistan
is a delight to work
with, particularly since
it is a new location
and we are able to produce
large, attractive stones.
Peridot has always ranked as one of the rarest gem crystals obtainable
by collectors, the most historic locality being St. John’s Island
off the coast of Egypt. These crystals were of excellent color with
very sharp, lustrous, well defined crystal faces. Another fine, and
more contemporary, locality is Myanmar (formerly Burma). Crystals from
this area are of superb color, but usually with heavily etched surfaces,
giving them an almost melted appearance. Well-formed crystals seldom
reach substantial size. Arizona has always been a prolific peridot
locality, but the geology is such that crystals do not develop.
Pakistan… with this new deposit we now have, perhaps for the first
time ever, peridot on matrix, with some of the largest crystals measuring
five inches in length! These larger specimens are generally riddled
with inclusions and fractures, but gemmy areas within have produced
cut stones of 100 cts and greater. The crystals tend to have poorly
defined structuring and faces, but a select few are sharp and lustrous.
These beauties have sent collectors into a frenzy, purchasing specimens
in sizes and qualities that were previously unknown.
Peridot has enjoyed a popularity which is making retailers and colored
stone dealers alike reevaluate their inventory. Knowing the alternatives
will allow you to offer another choice to that customer who loves green
but, for whatever reason, isn’t buying the more commonly chosen
alternatives (i.e., emerald, green tourmaline, or tsavorite).
In the jewelry industry, I think
all of my peers would agree that the busiest time of the
year is Christmas... unless of course, you’re preparing
for the Tucson Gem and Mineral show. This year’s show
will run from February 111. If you’ve never
been there, please take my suggestion and go.
Tucson show began in 1954 as a small mineral
display in a school cafeteria, run by a
gentleman named Bob Roots, Today it is
celebrating it’s 41st year and has
grown into one of the largest, most welI
known and best-organized shows in the industry
there are so many mineral affiliations
now connected with the show, I’ll
only name a few:
the late 1970s, gem dealers arrived, opening up a whole new level
of revenue for Tucson. From then on, Tucson became not only the place
to get the finest minerals and fossils, but also where retail
jewelry store owners and buyers could purchase for their customers
and replenish stocks after the Christmas season.
- Tucson Gem and Mineral Society (at
the Convention Center)
- Arizona Mineral and Fossil Show (at
the Executive and Quality Inns)
- Show of Integrity (Quality and Desert
gemstone exhibitors’ list is no less impressive,
two very hectic weeks; groups of dealers literally take over
just about every hotel in town in order to display and sell their
goods. Any information you might need on any of the aforementioned
organizations can be had by calling the Tucson Gem and Mineral
Society at 602-522-5773 or fax 602-322-6031. Come and see what
the excitement is all about. It’s a great chance to expand
your knowledge and further your appreciation of gemstones and
minerals. PALA INTERNATIONAL’s booth is #505 in the Tucson
Convention Center. Please call us with any questions beforehand
at 800-854-1598. We hope to see you there.
- AGTA (American Gem Trade Assoc.) (Convention
- GLDA (Gem and Lapidary Dealers Assoc.)
(Holiday Inn Broadway)
- Gem 6 Lapidary Wholesalers (Holidome
and Ramada Inn Downtown)