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Roger Weller, geology instructor
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Emeralds
Ashley Contreras
Physical Geology
Spring 2006

Emeralds

Emerald is green beryl

Chemical formula: Al₂Be₃Si₆O₁₈
hardness: 7.5 to 8

Birthstone of May

          The word emerald comes from the Greek word smaragdos meaning “green stone”.  It can range in color from dark green, light green, to yellow green and may have bluish tones.  Emerald is the official birthstone of May and is the anniversary gemstone for the 20th, 35th and 55th year of marriage.  On the Mohs scale of hardness Emeralds can range from a 7.5 to an 8.  The emerald’s green color is caused by the presence of chromium and iron.  Emerald is a variety of green beryl whose chemical formula is Al₂Be₃Si₆O_18.  Most of the world’s emeralds are found in Columbia, Brazil, and Zambia.  Emeralds often contain inclusions and other flaws.  These flaws however are not considered negative aspects but that they contribute the gemstone’s character.  These inclusions are generally gas bubbles that were trapped during the formation of the emerald.  The number of inclusions can also determine whether a stone is transparent or translucent. Emeralds can be cut in a variety of different shapes, ranging from the traditional rectangular step-cut, known as the "emerald cut," to round cuts, oval cuts, square cuts, and cabochons.  

Small emerald crystals

Photo credited to Roger Weller/ Cochise College

Emerald crystals from Columbia

Photo credited to Roger Weller/ Cochise College

Examples of low quality faceted emeralds

Photo credited to Roger Weller/ Cochise College

Examples of medium quality faceted emeralds

Photo credited to Roger Weller/ Cochise College

Example of high quality faceted emeralds

Photo credited to Roger Weller/ Cochise College

Faceted Emeralds

(the one on the left is translucent and the one on the right is transparent)

Photo credited to Roger Weller/ Cochise College

Carved emeralds

Photo credited to Roger Weller/ Cochise College

Emerald ring

Photo credited to Roger Weller/ Cochise College

          Archaeologists have traced the origins of the emerald to almost 2000 B.C. in both ancient Egypt and India. Emeralds have been cherished for as long as there has been a written history. The emerald is said to enhance love, drive away evil spirits, bring wisdom and faith, and bring popularity. Emeralds are also believed to bring strength, especially in old age, strengthen memory, quicken intelligence, and enhance courage.  Legend also sates that emeralds can improve memory and helps in predicting the future. 

Works Cited

www.gems4friends.com/birthstones.html

http://skywalker.cochise.edu/wellerr/GLGP-02.htm

http://lovejoyjewelry.com/all_about_birthstones.htm

http://skywalker.cochise.edu/wellerr/mingem/gemtp/emerald/emeraldL.htm

http://www.lapeergold.com/emerald.htm

http://www.misteremerald.com/imperfections-inclusions.htm

http://www.misteremerald.com/emerald-enhancements.htm

http://web.mawebcenters.com/sampleesmeraldaimports/emeralds.htm

http://www.galleries.com/minerals/gemstone/emerald/emerald.htm

http://www.rings-things.com/gemstone/e.htm

http://www.all-that-gifts.com/se/emerald.html
 

http://www.gemstone.org/gem-by-gem/english/emerald.html

http://skywalker.cochise.edu/wellerr/mingem/gemtp/emerald/emeraldL.htm

 

Ashley Contreras