Jade: "Stone of Heaven" - By: blog.RubyLane.com

Jade has an incredibly long, but sometimes confusing history. It is used for jewelry, as well as other ceremonial and decorative uses. The history of jade mining in China goes back 6000 years, and 4,000-year-old ceremonial jade items exist today. It is associated with the ancient cultures of Korea, New Zealand, and it was also used by the Pre-Columbian Americans.

Jade is a name, which applies correctly to two different minerals: Nephrite and Jadeite. It was not until the 1800’s that mineralogists established two completely different materials existed, both known as Jade.

Nephrite is the commoner of the two materials. It is composed mainly of calcium and magnesium and contains silicon and oxygen. Iron may be present, in place of the magnesium. This is the material most often used in ancient cultures. It is the only variety of Jade found in China. Nephrite is best known for the varying shades of green it possesses, but white, grey, black, and yellow to brown are also possibilities. Also, pieces that are white with a grey or green tint occur.

In New Zealand, Jade was important in the Maori culture. The stone was again Nephrite. Much of the material from New Zealand exhibits a grayish-green color, but it is known for dark green Nephrite, often referred to as “spinach jade.” Black is another color found in New Zealand. Guatemala is believed to be the source of jade in pre-Columbian America. While some Nephrite is found, archeological digs have revealed that most Guatemalan mines produced Jadeite.

Jadeite is primarily composed of sodium and aluminum, along with silicon and oxygen. A trace element of iron, titanium, and chromium affects the ultimate color producing even some bluish Jadeites, the blue color probably created by the presence of iron. Jadeite is rare, with about a dozen worldwide sources. It appears the Chinese were aware of this material before the 19th century, which they referred to as Imperial Jade. The imported Jadeite quickly found favor in China and the term Imperial Jade is now associated with a particular deep green variety. The material, which was mined in northern Myanmar (Burma) as early as the 14th century, was not traded with China and other mining area until the late 1700’s due to hostilities in the region.

In addition to the green color seen in Nephrite, some reddish orange and lavender colors exist in Jadeite. There are terms, which can be appropriately applied to particular shades of Jade, however, it is best left to those with years of study to determine the correct term because the difference in Jade colors is subtle and requires expertise to make an accurate assessment.

Imperial Jade or Emerald Jade refers to an intense green Jadeite, reminiscent of fine Emeralds. The material is normally semi-transparent. Apple Green Jade normally refers to a particular intense yellowish green jadeite. Yunan Jade may refer to Nephrite of Jadeite in a dark green color. Kingfisher Jade may refer to an intense medium-green Jade.

Moss-in-snow Jade may refer to a white translucent Jade with mottled streaks or areas of green. Mutton fat Jade may refer to a Nephrite, which is translucent white to a pale yellow color. New Zealand Greenstone, New Zealand Jade, or Spinach Jade may refer to the grayish green nephrite of New Zealand.

As if having two different minerals identified by the same name, with many specialized names associated with the different varieties of the two minerals does not confuse the issue enough, the identification of Jade is further complicated by the presence of imitators and misrepresented materials.

Serpentine and Aventurine are found in the same localities as Jade. These two green gems are often misrepresented as Jade. Other gems, which may be mistaken for Jade or misrepresented as Jade include Idocrase, Hydrogrossular Garnet, Chalcedony, Maw-sit-sit, Soapstone and Saussurite. Glass is also used as imitation Jade. The names, which these materials are often misrepresented with include Transvaal Jade, African Jade, Alaska Jade, Amazon Jade, California Jade, Colorado Jade, Fukien Jade, Garnet Jade, Honan Jade, Hunan Jade, Korean Jade, Mexican Jade, New Jade, Oregon Jade, Serpentine Jade, and Soochow Jade. Some of the localities used in these misnomers also do produce Jade, further confusing the issue.

These names are misnomers, which are inappropriate for use as identification of a material. It is not proper to use these misnomers in titles or categories. They may be used in descriptions, with quotation marks, but only when you have (properly identified the true nature of the material and are merely using the misnomer to comment on the way the material is improperly represented at times).

It is all right to represent a material, which you know to be Jade as Jade. It is better to identify it as Nephrite or Jadeite. Either of these terms may be followed by the term Jade.

Jade and its many imitators are also subject to a great number of enhancements. Dyeing, heating, and impregnation with waxes and other materials often used to enhance Jade. Some dyeing is detectable, as is wax impregnation. Some of the newer methods of impregnation using plastics and polymers are very hard to detect. Many imitations are identified by visual appearance, but measurements of the specific gravity, refractive index, or spectral analysis are needed to make correct definitive identifications.

Jade normally has a hardness of about 6-7, comparable to many quartz varieties. Jadeite is slightly harder, and will resist scratches to the surface better than Nephrite. Nephrite is tougher however, being more resistant to cracking or shattering. Nephrite is one of the toughest gem materials in existence. Standard cleaning methods are safe for Jade pieces, although steam cleaning may have a negative effect on stones impregnated or treated with waxes. Carving, seen in many Jade pieces, may create some weaker areas in a stone.

The title of this article is borrowed from a book of the same name, written by Richard Gump in the early 1960’s. An author, musician, philanthropist, and businessman, Gump was associated with the San Francisco family business of the same name, which was known for it’s specialization in Oriental arts, and the book is a classic in the field. We pay homage to his work by using his title for this short article and recommend that anyone with an interest in Jade or oriental arts read the complete original work.

Jade has an incredibly long, but sometimes confusing history. It is used for jewelry, as well as other ceremonial and decorative uses. The history of jade mining in China goes back 6000 years, and 4,000-year-old ceremonial jade items exist today. It is associated with the ancient cultures of Korea, New Zealand, and it was also used by the Pre-Columbian Americans.

Source: Notes from the Lane at http://blog.rubylane.com - Your complete resource for online sales success.
RubyLane.com is home to over 2000 online shops from around the world offering Antiques and Art, Vintage Collectibles and Jewelry in 2,000 categories.
Jade is available in all the areas of jewelry available on Ruby Lane. You will find many fine antique and vintage jewelry pieces, as well as work by contemporary Artisan Jewelers. The Jade itself is quite durable and suitable for daily wear.