The term Jade covers two different minerals – Jadeite Jade & Nephrite Jade. In its common term Jadeite Jade is known as the hard jade while Nephrite is known as the soft jade. Under the Federal Trade Commission rules in USA a seller describing his/her product as Jade must either be jadeite jade or nephrite jade and no other material.
Of the two minerals, Jadeite Jade is much more highly valued because of its vivid color, translucency and the very fine and compact texture within the jade. With the extraordinary economic progress of China for the past twenty years, the price of jadeite jade has been escalating year upon year, as demand for high quality jadeite jade cannot be quenched for those affluent mainland and overseas Chinese, who are the main buyers for fine and magnificent pieces of rare jadeite jade at international auction houses of Christie’s and Sotheby.
Contrary to popular belief, there are no jadeite jade deposits in China. Nephrite jade can be traced back to the ancient cultures of the Neolithic people (circa 5000BC – 1700 BC) in China. In these early Neolithic times, jade ornaments were used as an integral part of the imperial palace ceremonial and state regalia, religious rites and as funeral artifacts for the emperors.
Jadeite jade reportedly was introduced to China during the 13th century when the previously inaccessible jadeite deposits in Burma found its way into China. The traditional and the oldest source of jadeite jade come from Hpakan in the Kachin Hills in North Western Burma (Myanmar). Even to this day, it remains the only significant and singular source. Here at the numerous mines in Hpakan, where the Uru river cuts across its heartland, are the richest source of jadeite in the world which have produced the finest Imperial Jade for centuries.
There are perhaps some minor sources elsewhere notably Guatemala but their jadeite jade is mostly used as carvings and not of high gem quality. Nephrite is found in a number of countries in the world. In Canada nephrite is called BC Jade, in China it is called Soft Jade while in New Zealand it is called Pounamu, which means green stone.
Both minerals have different chemical composition and differ widely in their optical and physical properties though there look very similar by sight. Separation between Jadeite Jade and Nephrite Jade can sometimes be tough if you are not familiar with both minerals.
The following highlights the differences:
|Properties||Jadeite Jade||Nephrite Jade|
|Nature of mineral||Pyroxene group||Actinolite-tremolite series|
|Optical Character||Aggregates (Double R)||Aggregates (Double R)|
|Refractive Index||1.66 (Spot)||1.61 (Spot)|
|Moh’s Hardness||6.5 – 7||6|
|Specific Gravity||3.3 +/- 0.10||2.95 +/- 0.15|
|Absorption Spectra||Line at 437 nm||Rarely shows absorption|
Watch out for more posts on how to separate between the two.