Wednesday, September 5, 2012

The Composition of Jade

Nephrite boulder in Canada
Photo Credit: Jade-Jadeite
by Angela Magnotti Andrews

One of the toughest gem minerals, jade is an aggregate of tightly meshed, interwoven, and compact layers of microcrystals. Because of this mesh-like crystal structure, both jadeite and nephrite jade are resistant to fracturing, even after falling from great heights onto tile or marble flooring,These qualities make jade a great choice for cocktail rings.

It is this characteristic toughness that led Neolithic people groups to choose jade as a primary material for carving into axe heads and blades. Both types of jade have also long been fashioned into ritual objects, sculptures and statues, ornaments, and of course jewelry.

Since this course texture makes it nearly impossible for even the most skilled jade polishers to overcome undercutting, jade typically appears slightly greasy even at its highest shine. Nephrite typically appears greasier than jadeite, as though it's been smudged by sticky fingers.

The fibrous nature of jade also makes it difficult to facet, which is why most jade used in jewelry is formed into cabochons, beads, or discs. It has also been widely carved into scenic pendants or belt buckles.

Nephrite and jadeite come in a wide variety of colors, and despite their unique chemical properties, both are white in their purest chemical forms. The most commonly found jade of both types is pale green, and the emerald green jadeite stones are the most valuable.

Jade's unique composition and formation allows for more than variations in color. It is often speckled, mottled, or streaked. While these variations can enhance the value of a particular piece of jade, if this streaking or speckling somehow compromises the internal structure of the jade it will decrease the value of the piece.

Jade most often forms in large boulders, sometimes as large as a house. These large boulders are typically rough and grey on the outside, but once cut open with special tools they can yield a wide variety of different colors and grades of precious stone within.

Jade is a most spectacular gemstone on so many levels, each type holding its own secrets and intrigue.

Read more about Jade.
BIBLIOGRAPHY

1. "Jade." International Colored Gemstone Association. Accessed September 5, 2012. http://www.gemstone.org/index.php?option=com_content&view=article&id=121:sapphire&catid=1:gem-by-gem&Itemid=14.
2. "Jade (Jadeite, Nephrite)." University of Texas, Geology. Last updated August 20, 2009. http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/jade/jade_main.htm.
3. Katz, Bob. "Jade." Exploring the Southwest Desert USA. Accessed September 5, 2012. http://www.desertusa.com/mag98/aug/papr/geo_jade.html.
4. Keverne, Roger, ed. Jade. New York: Lorenz Books, 1995.
5. Leaming, Stan and Hudson, Rick. Jade Fever: Hunting the Stone of Heaven. Surrey, BC: Heritage House Publishing Co. Ltd., 2005.
6. "Mesoamerican Jade." Authentic Maya. Last updated January 28, 2011. http://www.authenticmaya.com/Jade.htm.
7. "Mineral Jadeite, The." The Mineral & Gemstone Kingdom. Accessed September http://www.minerals.net/mineral/jadeite.aspx.
8. Ralph, Jolyon and Chau, Ida. "Nephrite." Mindat. Accessed September 5, 2012. http://www.mindat.org/min-2881.html.

*Clip art courtesy of The Graphics Fairy





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