MAW-SIT-SIT

A. Maw-sit-sit rough (width - ca.12.5 cm). Unconventional Lapidarist. (© photo by Cindy Fowler, courtesy www.unconventionallapidarist.com)

B. Maw-sit-sit carving (width - 45 mm) for brooch; front and rear views of a sample studied by F.Colombo, C.Rinaudo and C.Trossarelli (2000). Sig. Scardina, jeweler of Turin, Italy collection. (© photo by C.Trossarelli, courtesy of Caterina Rinaudo)

DESCRIPTION: A metamorphic rock that has been recorded diversely as consisting of 1."albite that is irregularly interspersed with an alien,chromiferous mineral that induces the brilliant green color" (Gubelin, 1964-65) -- note use of singular nouns referring to the non-albite portion; 2.six chief constituents -- kosmochlor, chrome-jadeite, chrome amphibole, chromite, "symplektite" and a matrix of lighter colored minerals "(Zeolite, Chlorite, Albite, Serpentine) which fills the space between the minerals" (Hanni and Meyer, 1997); 3.albite, chromian-eckermannite, kosmochlor, chromite and natrolite (Colombo, Rinaudo and Trossarelli, 2000); [and] 4.kosmochlor [62 to ~65 per cent], chrome-jadeite [15 to ~18 per cent], chromian eckermannite [~4 per cent], chromiferous-albite [~1 per cent], plus chromite, etc. (Qi, et al., 2003). (Two things for the record: A.ureyite is listed as a constituent in a couple reports, instead of kosmochlor, which is the designation currently accepted by the International Mineralogical Association Commission on New Minerals and Mineral Names ; [and] B.symplektite is described by Hanni and Meyer (ibid.) as "a very fine mineral mixture which cannot be resolved microscopically.").   In addition, it seems only prudent to emphasize the fact that the relative percentages of the constituents of Maw-sit-sit may vary rather markedly within a rather broad range so the appearance and properties, such as its specific gravity, may also vary fairly markedly, specimen to specimen.
    Colors - diverse green hues, commonly described as brilliant or vivid, typically mottled with black and/or white spots and/or streaks
    H. (effective) 6-7 (as noted elsewhere, effective hardness is based on the hardnesses of the predominant constituents, which control checks used when the "unknown" is used as the "scratcher" rather than the material being scratched.)
    S.G. 2.5-3.5.
    Light transmission - opaque with some thin slices subtranslucent
    Luster - ranges from glassy to oily or porcelaneous
    Breakage - conchoidal to irregular.

OTHER NAMES: The designation Maw-sit-sit, used by people of the source area is apparently based on the name of the source locality in northernwestern Myanmar (previously Burma). Other previously applied names, none of which -- in my opinion -- should be applied, follow:

Chloromelanite - misnomer formerly applied in the marketplace; actually, this designation is a formerly used name for a pyroxene, which is not even one of the constituents of Maw-sit-sit.
Chrome-albite - name suggested -- but so far as I know not applied -- by Crowningshield (1965). He suggested it as more nearly correct, descriptionwise, that jade-albite and also as less confusing to those dealing with jade. This alternative designation was suggested on Crowningshield's acceptance of Gubelin's original description of the rock as "principally albite feldspar colored by a very fine-grained chrome-bearing pyroxene (chrome jadeite)." Considering more recent investigations and the resulting descriptions of this rock, this name seems no longer valid; it is fortunate this name was only suggested and never applied.
Jade-albite - name proposed by Gubelin (1965) about which consternation led to the discussion by Crowningshield (ibid.). Crowningshield's conclusion that application of this name would not have been wize seemed justified, and, on the basis of information now known about the rock, does not even pertain to its composition.
Kingfisher - name sometimes applied to Maw-sit-sit.
Kosmochlore-Jade - this name -- noted in, for example, Hanni and Meyer (1997) -- has one or more of the negative aspects of the already listed Jade-albite and Chrome-albite.
Kyet Tayoe - name given, chiefly by the local miners, to a light apple-green variety this gemrock that, typically has few if any black areas,. It is my understanding that most of those who have dealt with this variety prefer to call it by this name and NOT to consider it a variety of Maw-sit-sit.
Maw-sit-sit jade - name used by Qi et al. (2003); like "kosmoclhlore-jade" this term includes jade which can lead to misunderstanding/misrepresentation in the marketplace.

USES: Beads, buttons, cabochons, polished slabs and small carivings, some of which, especially in the past, have been marketed as jade substitutes or with names indicating them to be a kind of jade (see examples under the OTHER NAMES subheading.

OCCURRENCES: The occurrence as described by Gubelin (1964-65) indicate that weathering and water in the workings obscure the geological relationships so hypotheses of origina are based largely on mineralogical and petrological investigations. Two relatively recently suggested origins follow: “Maw Sit Sit was formed in connection with a high pressure low temperature rock metamorphosis which affected an ultrabasic body locally. New formations of minerals also took place after the culmination of the metamorphosis. Essentially it was a metasomatic reaction between serpentinites and albite dykes. ... The chromium which is found in most of the constituent minerals most probably stems from former chromite layers which have been dissolved during the metamorphic transitions. Remnants of chromite are sometimes found as relicts within the Kosmochlor spots. The Maw Sit Sit deposit is placed at the rim of a larger peridotite body which has been altered and serpentinized.” (Hanni & Meyer, 1997.) [and] "The jade is formed by the dynamic metamorphism and metasomatism characterized by mylonitic, metasomatic network and metasomatic pseudomorphous textures. . . . [i.e.,] by the superimposition and reformation of multistage dynamic metamorphism and low-temperature hydrothermal metasomatism." (Qi et al., 2003). In addition, Gubelin (op cit.) noted, by implication, that Maw-sit-sit boulders derived from the bedrock have been found in the Uru valley.

NOTEWORTHY LOCALITY: Mining area that is about a half a mile westnorthwest of Namshamawa, which is a small village in the Himalayan foothills of northwestern Myanmar (formerly Burma). This prime source is near the well-known Kansi and Namshawa imperial jadeite occurrences.

REMARKS: The designation Maw-sit-sit -- which, as already noted, is the name used by natives who mined and worked the material in Burma (now Myanmar) -- appears to have been introduced into the so-called Western World by the Swiss gemologist Eduard Gubelin who recorded his visit to the source area in two papers (1963 and 1964-65). Subsequently, as also noted herein, he and Crowningshield suggested alternative names, none of which has had noteworthy use in lieu of Maw-sit-sit. Indeed, that fate for one of those terms was predicted: Gubelin (1965) stated that his alternative jade-albite, which he considered more appropriate "does not exclude the admission that the original native name Maw-sit-sit may continue to be used in the future."

To date, I have found no record of treatments to enhance the appearance of Maw-sit-sit. Again, however, it seems prudent to mention the multimineral composition of Maw-sit-sit because it requires special procedures to keep the softer mineral parts from being abraded out and thus leading to undesireable irregularities on polished surfaces.

While compiling remarks for the entries for the individual Gemrocks treated on this web site, I early decided not to include most apparently recently concocted curative, astrological (etc.) attributes suggested for many of these materials and things fashioned from them; to me they seemed to have been been made up for the most part merely to increase sales -- i.e., to be marketplace ploys. When, however, one of my long-time research associates came up with the following "use" of Maw-sit-sit, I decided to repeat it here (albeit with “tongue in cheek”!!): “Maw-sit-sit when powdered, mixed with lac (or colorless fingernail polish) and applied to the fourth toe of one’s foot on each Friday that occurs on the thirteenth of a month, and the treatment is repeated over a period of two years, will immunize the person from future bouts of foot-in-the-mouth disease. There are, however, added requirements -- 1.the powder must include at least some of both the black and green parts of the Maw-sit-sit; 2.application is to be on only the fourth toe of the right foot of left-handed people and only the fourth toe of the left foot of right-handed people; and 3.application must be after at least six hours fasting (e.g., before breakfast or even early morning coffee). ... This use has been tested and found to have no ill effects, and compared to parallel use of jade (as a placebo), its application was found to be effective for more than 80 percent of those in the test group whereas use of the placebo showed no positive results. ...” (R. Dirk Ttitamgim, personal communication, 2004)

The kosmochlor versus ureyite designations for the chromian clinopyroxene constituent of Maw-sit-sit seems noteworthy in case anyone may uses a piece fashioned from this gemrock as a conversation piece: So far as its occurrence in Maw-sit-sit, this mineral was first identified as ureyite (named for Harold Clayton Urey, Nobel lauriate - 1934 - because of his discovery of heavy hydrogen); later, however, ureyite was found to be mineralogically the same as kosmochlor (so-named -- cosmo-"space" and chlor-green color -- because it was first found and thought to occur only in meteorites; the kosmochlor designation, having precidence, is the accepted name for this mineral (i.e., as just mentioned, ureyite has been discreditedas a mineral name) -- see International Mineralogical Association Commission on New Minerals and Mineral Names: www.geo.vu.nl/users/ima-comm/IMA-list.pdf).

SIMULANTS:
Malachite - Although suggested as a possibility, I know of no recorded use or misrepresentation of malachite for Maw-sit-sit. - [If ever so represented, malachite would be easy to distinguish from Maw-sit-sit by visual observation because of the characteristic green hues and banding of malachite; also, the hardness of malachite is much less than the effective hardness of Maw-sit-sit; etc.].

Jade - Although some jade might be so-represented, this seems unlikely. - [If it were so represented, visual observation should suffice so far as distinguishing virtually any jade from Maw-sit-sit.]

In my opinion, some of the simulants listed for jade (see THE JADES entry) would appear to be more likely simulants for Maw-sit-sit.

REFERENCES: No general reference.

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