MENU

History & Introduction


Jade is an umbrella term that represents a huge variety of gemstones, but the only pure forms of jade are found as jadeite and nephrite. Jade was first used several thousand years ago to make weapons and tools because of its toughness. The name "jade" comes from the Spanish word "piedra de ijada", which means "stone for the pain in the side". When the Spanish explorers noticed natives of Central America the name came while holding pieces of jade to their sides, believing that it could cure ills. According to the Chinese jade is named as "yu", which means "heavenly" or "imperial". Therefore, in Chinese culture it is popular as the imperial gem. In China, jade was found in the tombs of Shang kings.

Jade has a vital role in the history of New Zealand. It is available in South Island and was treasured for number of years by the Maoris of New Zealand, who called it as "pounamu", "greenstone" or "New Zealand jade". Pounamu was converted into Maori tools such as chisels and fish hooks, and weapons like short clubs and ornaments. This New Zealand jade is mainly a nephrite. Lake Baikal region of Russia spinach-green nephrite is obtained known as "Russian jade". Between the two varieties jadeite is the rarer, and the result it is more precious.

Recognise - As compared to other stones Jade is easily recognized due to its hardness and density. There are many other materials fraudulently sold as jade and it is difficult to recognize jade from its outside appearance. The reliable method to identify jade from other substances is due to testing of its specific gravity. A simple test is done to differentiate jadeite from nephrite is a chime test. When the nephrite is struck it emits a musical tone, whereas jadeite does not.

Availability - Nephrite is more common as compared to jadeite and it is extracted from Brazil, New Zealand, Australia, China, Canada, Russia, Taiwan, Alaska, Zimbabwe and Poland. The main source of jadeite is Myanmar (Burma), which is also the only source of imperial jadeite. Jadeite is also found in Japan, Kazakhstan, Turkey, Canada, Guatemala, Russia, Cuba and USA.

Usages - It is used in making traditional Chinese figures like the Buddha, dogs, dragons, bats, butterflies, peaches and discs. It is even made into all manner of practical items, like buttons, cups, plates and salt and pepper pots. Besides these carving figures it is used to make beautiful ornaments like the fashioned beads, cabochons for rings, brooches and fancy pendants and bangles.

Buying Guide

Color - Jade is available in various colors like white, green, orange, lavender, yellow, grey and black. The rich emerald green is the most highly valued and semi-transparent jade. It is known as imperial jade and is available only in Burma (Myanmar). Jade is more than one color in a single gem and where the distribution of color is highly valued. The inclination of color varies according to the region. Like in the West, rich and deep green jade is given more importance. However in Far East, pure white or yellow jade with a pink tone is preferred, along with green imperial jade.

Clarity and Lustre - Jade luster is vitreous (glassy). It appears vitreous to oily when polished. Jadeite is considered to be more vitreous (glassy) luster than nephrite and carrying more resinous (oily) luster.

Cut and Shape - Jade is enormously versatile and can be carved into complicated shapes. Rough jade is often bought as slices that gives no indication of the quality of the material inside. The internal quality of the jade is unknown until the rough stone is cut.

Treatment - Jade is frequently bleached with acid to erase the brown pigments. Bleaching makes the jade porous and more prone to breakage, hence after the bleach process the jade is mostly impregnated with a polymer that fills the fractures and improves its appearance. A "Chelsea filter" is used to determine whether jade is artificially dyed. When it is looked through this kind of filter, then dyed jade will exhibit in red. The jade industry from China uses a grading system to classify jadeite by the amount of enhancement it gets. As the system describes grade ‘A’ jadeite is not dyed nor impregnated rather it may receive a coat that is considered stable. For grade B jadeite may have been impregnated and bleached, however it is not dyed. Grade C jadeite is dyed and impregnated, and grade D jadeite is considered as not a real one.

Gemological Characteristics:

Chemical Formula NaAlSi2O6 Sodium aluminium silicate (jadeite) Ca2(Mg,Fe)5(OH)2(Si4O11)2 basic calcium magnesium iron silicate (nephrite)
Crystal Structure Monoclinic
Color Green, , grey, orange, yellow, white, lavender and black
Hardness 6.5 - 7
Refractive Index 1.652 - 1.688 (jadeite)
Density 3.30 - 3.38 (jadeite)
Cleavage Hardly observed because of absence of crystals
Transparency Opaque, translucent
Double Refraction or Birefringence 0.020 (jadeite) -0.027
Lustre Waxy, greasy
Fluorescence Greenish: Very weak; whitish: Glimmer; nephrite: None

Classification:

Customer Service

About Rasav Gems

Your Account

Education

Activities

Copyright © 2024. Rasav Gems. All Rights Reserved