Maw-sit-sit is a green gemstone that was named "maw-sit-sit" after the village where it was found in Northern Burma.
Since it is made of kosmochlor, chromian jadeite, chromian eckermannite, chromian albite, and other materials, maw-sit-sit is considered to be a rock, rather than a mineral. It is sometimes referred to as a variety of jadeite, but strictly speaking, maw-sit-sit is not jadeite, though it contains jadeite and is mined in the same area as imperial jadeite.
Jadeite is a mineral, whereas maw-sit-sit is a rock. The dominant mineral of maw-sit-sit is kosmochlor and this sets it apart from jadeite, which is sodium aluminum silicate. Therefore, maw-sit-sit is best considered to be related to jadeite. The kosmochlor component of maw-sit-sit is what gives it a beautiful emerald-green color with blackish-green patches.
|Polished Maw sit sit
Maw sit sit is a very rare, complex, polymineralic metamorphic rock composed mainly of:
Kosmochlor – the main colouring mineral species in Maw Sit Sit is kosmochlor, a sodium chromium pyroxene previously called “ureyite”. Kosmochlor is the primary component of both the brilliant emerald-green and dark green-black patches.
Chromian Jadeite – a chromium-enriched, but still Al-dominant jadeite (Al>Cr).
Chromian eckermannite – a chromium-enriched sodium-magnesium-iron amphibole-group mineral.
Chromian albite – a chromium-enriched albite.