Maw sit sit

Maw-sit-sit is a chromium-rich metamorphic rock with brilliant emerald green blotches and bands interspersed with dark green-black blotches. It is found in Kachin State, Myanmar.

It was first discovered in the early 1960’s by Eduard J. Gübelin a famous Swiss gemologist. Some of the other names by which this gemstone is known are mawsitsit, maw-sit-sit jade, chrome-jade, kosmochlore-jade, chrome-albite, jade-albite, chloromelanite.

This rock varies from brilliant emerald green to dark green and to almost black. Patterning varies from splotches to swirls and from to veins to bands. It is normally opaque but very thin splinters are translucent.

The dominant mineral species in maw-sit-sit is kosmochlor, a sodium chromium pyroxene. About 60% of maw-sit-sit is made up of kosmochlor and 15% by a chromium-enriched jadeite. Kosmochlor was known as ‘ureyite’ meaning “green from outer space,” This mineral was found in meteorites.

It has a hardness of 6 to 7 on Moh’s scale of hardness. Maw-sit-sit is translucent to opaque and used for carving or is cut as cabochons. Maw-sit-sit must not be cleaned using chemical agents, nor be exposed to rapid changes in temperature.