Earth Record
Mineralogy and formation
What most people get wrong about maw-sit-sit is that they call it jade, or worse, assume it is a single green mineral. It is neither. Maw-sit-sit is a polymineralic rock from Myanmar, not an approved mineral species. Its vivid green reputation comes largely from chromium-bearing components, especially kosmochlor, but the material itself is a complex intergrowth whose composition can vary specimen to specimen. In other words, maw-sit-sit is a rock name used in gem and carving trade, not a mineral formula to memorize once and apply everywhere.
Mindat summarizes the principal constituents in decreasing abundance as albite, chromian eckermannite, kosmochlor, chromite, and natrolite. Other descriptions also note chromian jadeite and related chromium-rich phases. That complexity explains why maw-sit-sit can show mottled bright green, dark green-black, white, and peppered textures all in the same piece. The green is commonly tied to kosmochlor and other chromium-rich silicates, while black spotting may reflect chromite or darker amphibole-rich zones.
The correction to the record is important. Although it is often marketed beside jadeite, maw-sit-sit should not be treated as a variety of jadeite. Its appeal is petrographic, not taxonomic: a tight, decorative, high-pressure metasomatic rock with striking chromium color zoning. It emerged in the gem world only in the mid twentieth century, when Eduard J. Gübelin documented it during work in Burma.
Properly understood, maw-sit-sit is not fake, but it is not simple. It is a named ornamental rock whose value lies in its intergrowth of feldspar, amphibole, pyroxene, and oxide phases rather than in a single mineral identity.
Chemical Formulaaggregate of Na(AlSi3O8) + NaNa2(Mg4Al)Si8O22(OH)2 + NaCrSi2O6 + FeCr2O4 + Na2Al2Si3O10·2H2OCrystal SystemaggregateMohs Hardness5.5Specific Gravity2.9-3.3Lustergreasy to vitreousColormottled emerald green, dark green, green-black, white, blackIMA StatusNot a mineral (rock) Hpakant-Tawmaw jade tractKachin StateMyanmar
Telling it apart
This one fools buyers because the color is doing all the talking. Bright green with black mottling gets called jade, chrome chalcedony, chrysoprase, or whatever sounds expensive that day. But maw-sit-sit is not just "green jade." It is a polymineralic rock, not a single mineral, typically an intergrowth of albite, clinochlore, kosmochlor, chromian jadeite, amphibole, and often chromite.
The confusion is maw-sit-sit vs chrome chalcedony, chrysoprase, and jadeite. The definitive test is texture and composition. Chalcedonies are microcrystalline quartz with a more uniform waxy body color. Chrysoprase gets its green from nickel. Chrome chalcedony gets its green from chromium but is still chalcedony. Jadeite is dominated by jadeitic pyroxene. Maw-sit-sit looks mottled, mixed, and busy because it is mixed and busy. Under magnification, it should not read like a uniform silica material.
Why it matters: these are not interchangeable names. Value, durability, and collector accuracy all change depending on whether you have a jade-related rock, a nickel-colored chalcedony, or a chromium-colored chalcedony. If a seller calls maw-sit-sit simply "jadeite" or "chrysoprase," they are flattening a complicated material into an easier sale. That should make you cautious immediately.
Spotting the real thing
Begin with the overall look. Real Maw-Sit-Sit usually shows a dense, mottled mix of bright to deep green with black, dark green, or whitish patches. The color is often lively but irregular, with a fibrous, granular, or webbed appearance. If a piece is perfectly even neon green with no internal complexity, it may be dyed serpentine, glass, or another imitation.
Check heft and temperature. Genuine Maw-Sit-Sit feels cool and notably solid for its size because it is a compact rock made of intergrown minerals. Resin or plastic copies warm quickly and often feel lighter. Because many authentic pieces are carved or polished, the surface can be smooth, but it should still feel like stone, not like coated plastic.
Inspect under bright light. Real material tends to have depth, mixed patches, and subtle structural variation rather than a flat painted look. Some areas may appear more translucent at thin edges, but most pieces are opaque to slightly translucent. Dyed imitations may show color collecting in fractures or an artificial glow that sits on the surface.
Use hardness as a clue. Maw-Sit-Sit varies because it is a rock, but it is generally tougher than soft serpentine sold in similar colors. A fingernail should not mark it, and it should resist easy scratching from copper. If it gouges too easily or feels soapy, be suspicious.
Specific to this material, look for the patchwork. True Maw-Sit-Sit often contains kosmochlor and other chromium-bearing minerals in an uneven mosaic. That means the pattern should look naturally assembled, not repeated. If multiple beads or cabochons show the same exact swirls or repeated printed pattern, they are likely imitation. Seller honesty also matters. If it is sold vaguely as "jade" without naming Maw-Sit-Sit or explaining that it is a rock aggregate, the identification may be sloppy or inflated.