Roger Weller, geology instructor
Inclusions in Emeralds
Kristi Blasdell
Physical Geology
Spring 2006
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PHOTO BY R.WELLER/COCHISE COLLEGE
Emeralds can be found in South America, Rhodesia, Pakistan, India, Africa, Egypt, Russia and Brazil. These Gemstones are considered to one of the worlds most popular sought after stones. As a member of the beryl family of minerals it is commonly known for its rich green color. The beryl mineral family usually has no color, but emeralds get their color from the presence of chromium. The name Emerald comes from the Greek word “Smaragdos” which is translated to means “green stone”.
Unlike
other precious gemstones, inclusions and small fractures in an emerald
crystal does not detract from the value of the stone. In fact the minor
imperfections found within the stone are what give it “personality"
and prove that the gem is a true stone and not an imitation. The inclusions
are generally small gas bubbles that were trapped during formation, but can
also be iron pyrite or water. Whether a stone is translucent or transparent
depends on the number of inclusions. Thus, only a few inclusions and the
stone will be almost see through. However, a stone with too many inclusions
will appear almost opaque or “cloudy”. The inclusions in an emerald
are generally referred to as a “garden”, but cause the stone to be
fragile or sensitive. So, jewelers in the 17th century
invented the “emerald cut”, which is a rectangular step-cut, to account for
the gem’s easily broken nature.
PHOTOS
BY R.WELLER/COCHISE COLLEGE
In an attempt to minimize the visibility of inclusions a technique referred to as “clarity enhancement” is generally applied to an emerald stone. Because the inclusions are usually small gas bubbles or fissures oils are used to fill them in to make them less visible. The most popular oil used to fill in the blemishes is cedar wood oil. The oil fills in the bubbles or fissures to reduce their visibility, but will preserve the clarity of the emerald.
EMERALDS WITH VISIBLE INCLUSIONS
PHOTO BY R.WELLER/COCHISE GEOLOGY
HIGH QUALITY EMERALD WITH FEW VISIBLE INCLUSIONS

PHOTO BY R. WELLER/COCHISE COLLEGE
HARDNESS= 7 – 7.50 BIRTHSTONE FOR MONTH OF MAY
WHAT MAKES A HIGH QUALITY EMERALD? WEIGHT, PROPORTION, COLOR, BRILLANCE, AND CLARITY
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Mica
inclusions in a Brazilian emerald
International School of Gemology
http://www.yourgemologist.com/emerald.htm
SPIRAL
The spiral inclusion is caused by tiny water drops trapped during formation
FINGER
PRINT
This is a Natural "Finger Print" formed by tiny liquid-filled bubbles
TUBE
GROWTH
STRUCTURE
DROP
OF OIL EFFECT
This stone has what is called an "Oil Drop" effect. When observed in
daylight the stone is observed with a silky appearance. Light shine through
the stone and gives it a “sunlight” glow.
LAST 5 PHOTO’S OF INCLUSION TYPES BY:
http://www.emporia.edu/earthsci/amber/go340/beryl.htm
REFERENCES
http://www.emporia.edu/earthsci/amber/go340/beryl.htm
http://skywalker.cochise.edu/wellerr/GLGP-02.htm
http://www.lapeergold.com/emerald.htm
http://www.misteremerald.com/imperfections-inclusions.htm
http://www.misteremerald.com/emerald-enhancements.htm
http://www.emporia.edu/earthsci/amber/go340/students/skaggs/may.html
http://web.mawebcenters.com/sampleesmeraldaimports/emeralds.htm