Characteristic gemological properties of rubies
from Burma (Mong Hsu and Mogok)
 Inclusions in the rubies
- Mogok (classical mine): calcite, sphene, spinel, pargasite, and pyrite
- Mong Hsu (new mine): isolated rutile grains, Mg-chlorite, white mica, fuchsite,
and fluorite
Rutile exsolutions
- Mogok (classical mine): isolated nests
- Mong Hsu (new mine): not present
Solid inclusion frequency
- Mogok (classical mine): often present
- Mong Hsu (new mine): rarely present
Whitish particle (in not-heated rubies)
- Mogok (classical mine): absent
- Mong Hsu (new mine): present as "streamers" and "snow flakes"
Fluid inclusions
- Mogok (classical mine): present
- Mong Hsu (new mine): frequently present
Growth structures (dominant)
- Mogok (classical mine): prism (a), basis pinacoid (c)
- Mong Hsu (new mine): pyramides (n, r, omega), basis pinacoid (c)
Growth characteristics
- Mogok (classical mine): disturbed growth structures ("swirled")
- Mong Hsu (new mine): undisturbed regular growth and habit variations
Color distribution
- Mogok (classical mine): regular or swirled
- Mong Hsu (new mine): regular complex zoning (not-heat-treated:
blackish-violettish core)
Heat treatment
- Mogok (classical mine): often applied for removal of rutile nests
- Mong Hsu (new mine): very often applied for removal of blackish to violettish
cores
Twinning
- Mogok (classical mine): parallel twinning quite often
- Mong Hsu (new mine): parallel twinning rarely present
Interpretation of ruby formation
- Mogok (classical mine): metamorphic reactions in calcsilicate marbles and
metasomatism
- Mong Hsu (new mine): hydrothermal precipitation in veins crossing marbles
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