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Roger Weller, geology instructor

wellerr@cochise.edu

Jade
by Shea Dangelo
Physical Geology
Fall 2016
  
 

                                                                                

                                  Jade Reverence                                        
 

                "Jade" is a term used for one of the many wonders produced by the natural processes of the earth. It is a very durable, and often beautiful gemstone that has been fashioned into tools, sculptures, jewelry, gemstones, and other objects for many millennia. 

 

Jadeite and Nephrite: What’s the Difference?
 

When one hears the term “jade”, they often think of the brilliant hues of green that have made the gem famous, but “jade” is actually composed of two categories: nephrite and jadeite.  These two categories contain a range of colors from the various shades of white to dark green, sometimes gray, pink, lilac, red, blue, yellow, orange, or black of the rarer and somewhat tougher jadeite, to the mid to dark green or grey-green, white, yellowish or reddish of nephrite.  
 


 

Jadeite and nephrite are both regarded in China as 'zhen yu' (translated as 'genuine jade'). They may bear a considerable resemblance to each other in terms of their appearance, their hardness and the properties they exhibit when being processed. And, both are tough, since they consist of dense, close-grained, matted aggregates. The ways they differ from one another is in their chemical composition and colors. Nephrite is a magnesium-rich amphibole whose chemical composition is Ca2(Mg, Fe)5Si8O22(OH)2, and jadeite is an aluminum-rich pyroxene whose chemical composition is NaAlSi2O6. Master Chinese craftsmen who worked with jade daily recognized that some of the jade obtained was harder, denser, worked easier, and produced a higher luster upon polishing (jadeite). This allowed them to make a distinction between jadeite and nephrite long before scientists differentiated the two in the 19th century.
 

 As for color, as was stated, each category of jade carries its own color range. In both, only in the very finest jade is the color evenly distributed, though the “flaws” often found in both jadeite and nephrite may not always be regarded as so.  On the contrary, veins, blemishes and streaks running through them create patterns that may be considered particularly valuable to some.
 


 

 

Uses Throughout the Ages:
 

 Originally admired for its toughness (on Mohs Scale of hardness it ranges from 5 to 7 depending on its composition), it was used mainly for tools and weapons in many cultures. "Toughness" is the ability of a material to resist fracturing when subjected to stress. "Hardness" is the ability of a material to resist abrasion. Early toolmakers took advantage of these properties of jade and formed it into cutting tools and weapons. It was used to make axes, projectile points, knives, scrapers, and other sharp objects for cutting.
 


 

Later, because of the color and translucence of some of the pieces found, the jade began to be cut, shaped, and polished for other purposes such as jewelry, ornaments, statues, and carvings.
 

                                   
 

 In ancient China, jade was referred to as 'yu' (translated as the 'royal gem'). Nephrite was the first jade uncovered in ancient China, and was the traditional jade used and carved, so much so that the deposits of it are now but depleted in China. In the 14th century, jadeite coming from Burma began to be traded to China on a wide scale. The harder, denser, and easier worked composition of the jadeite became preferred by Chinese artisans and the Chinese people, and is now the main type of jade being traded in present day China.    Similar to the way royals of European countries wore precious gems such as rubies and diamonds as symbols of status, jade became the symbol of status, power, purity, spirituality, and health for China. The most wealthy and influential members of Chinese society would even be buried in jade suits.  In today’s society, jade in China sells for about the same price per carat as diamond in the United States.
 


 

            Although the reverence for jade in China is unmatched, other cultures such as the Mayas, Aztecs and Olmecs of Central America also honored and esteemed jade more highly than gold, as is the sentiment toward jade in China. The Aztecs carried jade figures of gods to whom they worshipped or carved masks and ornaments that would be used in such rituals.
 

 
 

          Along with other earlier cultures, New Zealand's Maoris began carving weapons and cult instruments from native jade in early times, a tradition which has continued to the present day. In other regions and cultures, such as ancient Egypt, jade was admired as the stone of love, inner peace, harmony, balance, wisdom, and was said to provide luck and protection for those that kept it in their possession.
 

            The infatuation with this gemstone through the ages is a testament to man’s admiration of the beauty that the earth supplies through its natural processes.  A beautiful rock to some and a sacred stone to others, jade will continue to capture the hearts of humankind, whether aesthetically or spiritually, for years to come.

 

Works Cited

http://www.visualcapitalist.com/the-history-of-jade-the-emperors-stone/

http://www.eglasia.com.hk/jade_culture.html

https://www.joya.life/en/blog/mesoamerica-and-jade-seven-cultures-and-one-stone/
http://geology.com/gemstones/jade/

http://www.gemstone.org/index.php?option=com_content&view=article&id=121:sapphire&catid=1:g?em-by-gem&Itemid=14
 

Photo Credits:

https://www.gemrockauctions.com/auctions/jade-gemstones/jade-rough/item-205833
https://www.gemrockauctions.com/auctions/jade-gemstones/jade-rough/item-199644

http://www.visualcapitalist.com/the-history-of-jade-the-emperors-stone/

https://www.pinterest.com/ladyoftheabyss/crystals-and-gemstones/

https://cycleback.wordpress.com/2013/01/30/identifying-jade/

https://www.quora.com/What-is-the-significance-of-jade-in-Chinese-culture

https://www.etsy.com/listing/228606651/sale-20-off-shang-dynasty-bronze-jade

http://coloradogambler.com/gemstones-minerals-montezumas-aztec-gold-and-gems/aztec-jade-mask/

http://www.metmuseum.org/toah/works-of-art/1977.187.33/

https://uk.pinterest.com/pin/75716837455044728/