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Roger Weller, geology instructor                             

wellerr@cochise.edu
 


Inclusions in Emeralds

Kristi Blasdell

Physical Geology

Spring 2006

 

 

INCLUSIONS IN EMERALDS

 

                                                                                                       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

                                                                              

 

TYPES OF INCLUSIONS

Mica inclusions in a Brazilian emerald
International School of Gemology   http://www.yourgemologist.com/emerald.htm
 

 

spiralSPIRAL

 The spiral inclusion is caused by tiny water drops trapped during formation

 

 

fingerprintFINGER PRINT
This is a Natural "Finger Print" formed by tiny liquid-filled bubbles

 

 

tube TUBE

 

 

 

growth structure GROWTH STRUCTURE

 

 

drop of oil effect 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:

Emporia State University

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