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Rubies quality

An approximate ranking of important ruby"Beryl Island" Madagascar was long considered
origins is given below. This applies only formineralogical nirvana. And today, it is
the finest untreated qualities from eachequally  known  for  its  gem  wealth.
source and is but a general approximation. In
other words, a top-quality Thai/CambodianPrior to this year, Madagascar produced
ruby can be worth far more than a poor Mogokmainly fine blue sapphires and pinks. But now
stone.two important ruby deposits have been
discovered. The first is about 10-30 km.
Mogok,  Burmainland from the coastal town of Vatomandry,
while the second is roughly 45-70 km. from
Sri  Lankathe town of Andilamena. Vatomandry is said to
produce the better-quality stone, being
Madagascarlighter and brighter (more reminiscent of
Burma), while the Andilamena stone is
Nanyazeik,  Burmasomewhat darker and not as clean. Rutile silk
seen in some pieces suggests that star stones
Everything  elsemay be forthcoming. Much of the material from
both  deposits  is  heat-treated.
Mogok
It is still too early to properly rank
When we talk ruby, we talk Burma. ForMadagascar in the ruby world, but the stones
connoisseurs, no other will do. In the daysI have seen so far suggest that there is
of yore, matters were simple. Burma meantgreat  promise.
Mogok. This storied deposit was known for
over 1000 years as the home of the finestVietnam
ruby  on  the  planet.
Beginning in the late-1980's, fine ruby began
While Mogok is the traditional source of thepouring out of two different deposits in
world's finest rubies, good stones are rareVietnam. Although Vietnam's ruby originates
even from this fabled area. Pigeon's bloodfrom two different mining areas, Luc Yen
was the term used to describe the finest(north of Hanoi) and Quy Chau (south of
Mogok stones, but has little meaning today,Hanoi), both sources display similar
as so few people have seen this bird's blood.characteristics.
Mogok-type rubies possess not just red bodyThere's nothing like time to put things in
color, but, by a freak of nature, redperspective. In the late 1980's, Vietnamese
fluorescence, too. In addition, the bestruby literally exploded on the world gem
stones contain tiny amounts ofmarket. The best Vietnamese ruby approaches
light-scattering rutile silk. It is thisfine Mogok, but since the early 1990's most
combination of features that gives thesehave tended towards pink. Today, little
rubies their incomparable crimson glow. Infacet-quality is produced, and even the
Mogok rubies, the color often occurs in richcabochon material rarely competes with that
patches and swirls, and color zoning canavailable from MA?A×®g Hsu. Some pinkish
occasionally be a problem. The shape of Mogokstar  material  is  also  produced.
ruby rough generally yields well-proportioned
stones.Kenya  &  Tanzania
In addition to faceted stones, the MogokStones from these sources are magnificent
Stone Tract also produces the world's finestwhen clean, but facet-grade material is rare.
star  rubies.Like Burma, much of this material is strongly
fluorescent. Star stones are not produced
Mang  Hsufrom  these  deposits.
When the Mang Hsu deposit came on stream inOne specific deposit is worth mentioning.
1992-93, it took the ruby world by the storm.Beginning in the mid-1990's, mines near
Suddenly, we were awash in a sea of red theSongea began to produce material with a dark,
likes of which had never been seen before.garnety color veering towards orange. While
And fine stone it was, too. This was not thethis material is ruby of a sort, it is
garnet-like hue of Thailand, but a rich,marginal  due  to  its  high  Fe  content.
fluorescent  red.
Afghanistan
In 1992, the Mang Hsu (Maing Hsu) deposit in
Burma's Shan State began producing goodJagdalek has produced rubies that rank with
material. This has continued to the present,fine Mogok stones, but facetable material is
so much so that close to 90% of the fine cabin short supply. Similar to Vietnamese
and facet-grade ruby in the world market isrubies, many of these stones contain small
from this deposit. But most cut stones areareas of blue color. They are also strongly
under  two  carats.fluorescent, and if the deposit ever produces
clean material, watch out. No star stones
Mang Hsu material can be extremely fine, buthere.
virtually all is heat treated, and most is
also  flux-healed.Thailand/Cambodia
Nanyazeik  (Nayazeik)This material's main attribute is its high
clarity, but the flat crystal shapes
In the past year or so, rubies have startedgenerally yield overly shallow stones. Due to
to come out of Nanyazeik in Burma's Kachinthe high iron content, which quenches
State. I did see one fine purplish red piecefluorescence, most stones tend to have a
from this deposit on my last trip to Burma ingarnet-red color. An additional problem is
June, 2001. Only time will tell whetherthe total lack of light-scattering silk
Nanyazeik has the makings of an importantinclusions (star stones are not found).
source. Other than ruby, Nanyazeik hasAlthough heat treatment does make
produced some super red spinels, equal toimprovements, it is not enough. In Thai
anything  from  Mogok.Cambodian rubies, only those facets where
light is totally internally reflected will be
Sri  Lanka  (Ceylon)a rich red; the others appear blackish, as
with red garnets. Thai stones are actually
The classic case of giving a dog a bad name.less purple than most Burmese rubies.
Some of the world's finest rubies have comeHowever, Burma-type rubies appear red all
from Sri Lanka's gem gravels, but because ofover the stone. Not only is a rich red seen
the erroneous "pink sapphire" moniker, theyin the areas where total internal reflection
have been largely overlooked. Top-grade Srioccurs, but due to the red fluorescence and
Lankan reds are virtually indistinguishablelight-scattering silk, other facets are also
from their Mogok brethren, but most tendred.
towards purple or pink. As with Sri Lanka
sapphires, color accumulates in large stonesWith the decline in Burma production during
and so they can be quite magnificent in sizesthe 1962-1990 period, the market became
of five carats or more. Due to theconditioned to Thai/Cambodian rubies, with
bipyramidal shape of the rough, many stonessome people actually tending to prefer them
are cut with overly deep pavilions. Sri(in the land of the blind, the one-eyed man
Lankan ruby is strongly fluorescent and starsis king). Thai/Cambodian rubies are
are  common.acceptable only when good material from the
Burma-type sources is not available. Today,
Madagascarproduction from the Thai side of the border
is zero, and that from Cambodia is
When I was teaching gemology in Bangkok, Inegligible. One occasionally hears statements
used to point to an island off the coast ofabout how Cambodian stones are superior to
Africa and inform my students that, if theythose from across the border in Thailand.
wanted to hunt gems, this would be a greatThis is untrue. The deposits are essentially
place to start. Known in olden times as theone, directly straddling the border.



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