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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 and minerals.
    We distribute The Gem Spectrum free within the United States to members of the gem and jewelry trades. If you would like to be added to our mailing list, please contact us.

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Tucson, February 1997 was the first time many people had ever seen it. At first glimpse one gets the impression that this opaque, vivid, mossy green, material is somehow related to jade; and although it does indeed form within the jade deposits of Hpakan, Upper Burma, maw-sit-sit is a very different cousin.
    It was in 1962 when Dr. Edward Gübelin first noticed the material was being referred to as maw-sit-sit, which was in fact, the mining area from where it originated. Then, as well as today, classification would prove to be quite a challenge due to maw-sit-sit’s unique composition. In this issue of the Gem Spectrum, we will attempt to help you understand this most unique gem material.

Gemology
Maw-sit-sit may be distinguished from jadeite and nephrite by its appearance as well as its physical and optical properties. It has a refractive index that ranges from 1.52 (most common) to 1.74 (least common) depending on the aggregate mineral composition. The density is therefore also somewhat variable, falling between 2.5–3.5g/cm3. Most cutters agree that the hardness falls between 6 and 7 on the Mohs’ hardness scale.

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Rough and cut maw-sit-sit (Photo: Harold & Erica Van Pelt)

    Its color is most probably caused by the presence of chromium. Dr. Vince Manson, of the GIA, first suggested in 1979 (based on unpublished data) that maw-sit-sit might contain ureyite, which is a sodium chromium pyroxene (NaCrSi206) where chromium (Cr) replaces aluminum (Al) in the chemical composition. Ureyite, which was named in honor of Professor H.C. Urey, is today properly termed kosmochlor. The name kosmochlor (green from outer space) is derived from the fact that it was originally found only in meteorites. Dr. Henri Hanni, of the SSEF, in Basel Switzerland, noted in 1986 (based on unpublished data) that maw-sit-sit is composed of six main components. They are as follows: chromite, ureyite, chrome-jadeite, symplektite, chrome amphibole, and a matrix of lighter minerals.

Geology & mining
Maw-sit-sit is an aggregate of numerous minerals found in the famous jade mining region of Tawmaw in the Himalayan foothills of northwestern Burma. This small mining area lies approximately half a mile northwest of the village of Namshamaw. The maw-sit-sit mining area is found in part of what is known as the Namshamaw dike. Maw-sit-sit, like the jadeite found in this region was formed due to high pressure regional metamorphism. This region lies on a plateau at an elevation of approximately 3000 feet within the Uru river drainage basin.
    Maw-sit-sit is a byproduct of jadeite mining and is quite rare in comparison to jade. The mining techniques used today are similar to those employed three decades ago when Dr. Gübelin first stumbled upon the unique gem material, with the exception of modern machinery used to excavate and tunnel through the thick overburden.
    Production has increased recently with demand, however, fine quality maw-sit-sit remains difficult to acquire. There are actually two types of maw-sit-sit being found:

  • Maw-sit-sit – the rich green hue with a medium tone containing contrasting black streaks or spots
  • Kyet Tayoe – the lighter apple green hue with a fainter tone containing little or no black streaks or spots

Of the two, maw-sit-sit is certainly more attractive. Until demand increases, it will be difficult to determine the potential supply but thus far it seems to still be quite a rare occurrence.

More about the Myanmar name change
Myanmar, which was once (until only a few short years ago) a nearly inaccessible country, is now becoming a mechanized nation booming with western influence . This endearing country with its sacred adherence to religion and tradition has undergone many changes.
    In 1989 the official English name of the country was changed from the Union of Burma to the Union of Myanmar. There has actually been no change in the Burmese name for the country since Myanmar is actually the country’s official name and is found documented in Marco Polo’s early 13th century writings. In Burmese literary contexts, “Myanmar” is used to refer to the whole country. Note: As of this printing (May, 1997), President Clinton imposed a ban on new U.S. investment in Myanmar charging that Burma’s leaders have refused to open a political dialogue with Burmese democrats including Nobel Peace Prize winner Aung San Suu Kyi.

Geography
Myanmar has an area of 671,000 sq km, between Thailand and Laos to the east, India and China bordering the north, and Bangladesh to the west. The Tropic of Cancer crosses the country just above Mogok while intersecting also with the Chin, Kachin and Shan states. The Himalayas rise to the north of Myanmar where at the border between Tibet and Myanmar stands Jkakabo Rasi; which rises to a grand 5889 meters and is the highest mountain in South-East Asia. From the earliest mining days, Myanmar has supplied an endless bounty of gem materials which ornament our surroundings as well as our bodies. Now in less supply, fine rubies, sapphires, and spinels, which find there way out of the country, command much higher prices. The diversity of Myanmar’s gem bearing mineral deposits have always offered countless possibilities to the creative designer and maw-sit-sit is proving to be no exception.

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
A delight for the eyes and a challenge for the cutter! This multi-toned opaque material is made up of green and black pyroxenes and white albite which constitutes a single stone with varying hardness’ and toughness. It is most efficient to cut maw-sit-sit on diamond laps as they cut through most components equally. Even then, “soft spots,” usually the lighter green area, grind away more quickly and necessitates extreme caution when cutting to exact specifications. Pre-polishing is extremely important and is best accomplished on soft diamond impregnated pads, with a final polish of 50,000 grit. Plenty of water and high speed rpms can smooth out the pulling and undercutting so common in a gem material comprised of so many different minerals. Happily, however, maw-sit-sit has none of the toxic properties encountered in malachite. A final finish similar to jadeite is possible in the finer materials but it must be understood that some leeway should be observed in this area as each piece cuts differently then the one before. Thus is the charm of maw-sit-sit.

Meg Berry

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Map of Upper Burma showing the jade mines in the far north. Maw-sit-sit is mined in the vicinity of Hpakan. (map © Richard Hughes)
maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Updating the Mogok area’s underground mining methods
On my last trip into Mogok, Dr. Saw Naung U had urged me to visit the famous “insurgent” mine – “Ka Doke Dat.” While this mine was outside a government protected area, the doctor assured me that I would be safe if he was my escort. The kind doctor had extended this invitation on my previous trips (11 to be exact) but time had always prohibited it. This time I was determined to take him up on it, I might be able to get a ruby crystal in situ.
    We arrived at the mine via rugged roads that parallel all the various shafts that go down the contact zone. I noticed many local women waiting along the perimeter of the mining area and was told that they were waiting for the miners who had already sorted for large rubies below. At the end of their shift, they will gather up the rocks of white marble material into buckets. The buckets are then given to the ladies who take them home and carefully re-sift them for smaller stones. After their sorting, the remaining white marble gravel is thrown outdoors. As a result of this daily ritual, the entire village looks as though it’s been sprinkled with crystalline snow. It is spectacular in daylight.
    The mine zone is perhaps two kilometers long, and is divided into approximately 30 areas. They are mining down deep on the contact zone formed between the coarsely crystalline marble and the so-called Mogok gneiss. The contact metamorphic zone that contains rubies in situ dips steeply (as much as 45 degrees in some areas). The zone that contains the rubies is about two feet thick, however, rubies are very rare and interspersed. Most of the ruby crystals are less than one gram and not of gem quality.
    I was the first American allowed to go down into the Ka Doke Dat Mines. I chose the second deepest one, and I must say, that the native engineering is indomitable. Descending down a series of over 45 bamboo ladders, I found not even one with a loose rung or any movement. My guide informed me that the bottom was 580 feet on a measured tape from the surface. A series of small winches would bring up the buckets one by one with broken pieces of marble from the working face. The faces are worked with an electric drill, which have tungsten carbide bits, since the marble is rather soft. They drill in about 2 1/2 feet, stick in 1 1/2 sticks of dynamite, and blast. I am sure many rubies are damaged this way; however, by working open faces and blasting large sections down one at a time, they expertly keep the breakage to a minimum.
maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Opening 7-B at Mogok’s Ka Doke Dat mine.
(Photo: Bill Larson)

    This mine would be impossible to be economical, except for the fact that it has been worked by the insurgents. The dream of finding a great ruby has been kept alive by one of the 30 pits each day producing something of value. Unfortunately, I did not see anything good this day; however, there had been a few pieces in the weeks before. I was allowed to buy a specimen which has now been sold to the Harvard University Collection. With time and energy, I am sure that the very intelligent Burmese will indeed start preserving some excellent mineral specimens. We may soon see some wonderful pieces for our museums as more and more people discuss what is interesting for the world market. The problem that we have encountered so far, is that the pieces sell way beyond the prices that most mineral collectors have been willing to pay.
    Burma, with all of its differences, continues to be a never-ending learning process, and once in a while, we find something that is most exciting. But let me leave you on a humorous note. My friend Yew Sett has a $50,000 garden. How did this come about? He paid this amount for a beautiful ruby crystal specimen which measured 2 x 2.5 inches. It was a perfect hexagonal pyramid on white marble that looked like it would produce a gemmy ruby if cut. Maybe not realizing the money a mineral specimen of this caliber would fetch, he gave it to his cutters hoping to retain a fine cut stone. The grinding commenced... and continued... and continued... until all that was left was ruby dust. This he proceeded to sprinkle over his garden. Smiling, he admits it is the most expensive fertilizer a gardener has ever known.

  • See also Bill’s Mining Notes from Vol. 1, No. 2 of Gem Spectrum

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
“Of all scientific subjects, geology, geologists, and gemologists, are probably the least narrow and prosily materialistic. In the pursuit of geological studies, gemology, par excellence, there comes into play a mysterious inspirational power derived from close association with Nature’s huge creations and forces. Set with sublimest scenery, in a supernatural atmosphere of beauty and with the marvelous unfolding of Nature’s ways, the awakening consciousness of the eternal powers, the majesty of conception, the everlastingness of time, material, force and movement, and of resulting life itself, create an intimate approach along the paths of science, to the vary gateway of the unfathomable secrets and mysteries of life. These awe-inspiring, magnetic influences and the dawning comprehension of universal greatness, transmitted through these poetic and scientifically romantic contacts, are those who cultivate the reverential expanding vision. You who strike through and bring to the surface in the fullest refinement of the finer traits and aspirations. Making he or she at his or her best... The Gemological scientist.”

Sir Frederick Gleason Corning
1920

maw-sit-sit, Burma, Pala International, ruby, gems, mineral specimens, sapphire
Special thanks to...

  • Edward Boehm, Joeb Enterprises, for the gemology segment