Gem of the Month

 

Each month this section will feature either a topic of interest to gem lovers or one special gemstone with background on the material and its value.

Go to: Homepage -- what's new in faceted gems -- what's new in designer cabochons and gem carvings -- gem of the month -- gem of the month archive -- birthstone of the month -- key to all the codes used on the ACS site -- definitions of terms used on the ACS site -- how to order -- about ACS -- about the ACS cutters -- settings for these gems --faceting information -- purchase UltraTec equipment

 

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Mawsitsit

March, 2000

In 1963 Dr. E. Gubelin, the famous gemologist, was traveling in Burma (Myanmar) and noticed a bright green rock with black inclusions being mined at a locale named Maw-sit-sit. It took over 30 years for this beautiful material to become available to the world at large. That this has happened in a big way was driven home to me recently when I saw pieces of Mawsitsit jewelry being sold on a home shopping channel. This material which gets its lovely green color from chromium is not jade, but is similar in its toughness, chemistry and the uses made of it. Prime specimens can take a superb polish and the dramatic contrast of bright green and black is unique in the gem world. Virtually all of the world's supply comes from the original site.


Value

The best specimens have nicely contrasting areas of saturated green and black and good polishes. Carvings, as always, command more per carat than cabs or beads.


Gemological Data:

Makeup: a rock made of the mineral kosmochlor with varying amounts of feldspar, chromite and other minerals

Luster: waxy to vitreous

Hardness: 6

Crystal structure: an aggregate very similar to jade in its fibrous texture

Fracture: granular

Cleavage: none

Density: 2.77 (+38, -.31)

RI: 1.53 to 1.74 often with multiple readings due to different materials present

Birefringence: none

Pleochroism: none

Dispersion: none


Stones Currently Available

{Search our Catalog}

Go to: Homepage -- what's new in faceted gems -- what's new in designer cabochons and gem carvings -- gem of the month -- gem of the month archive -- birthstone of the month -- key to all the codes used on the ACS site -- definitions of terms used on the ACS site -- how to order -- about ACS -- about the ACS cutters -- settings for these gems --faceting information -- purchase UltraTec equipment