What is Jade
Jade has no strict definition. In China, a wide variety of minerals are so-called as Jade; there are different definitions of" jade" in ancient and modern literature, including:
"Jade, the most beautiful of all the stones", Shuowen jiezi (tr: Explaining Simple and Analyzing Compound Characters), by Xushen, East Han Dynasty.
"Jade, hard and smooth", The book of changes, by Kong yingda, Tang Dynasty.
"Jade: A fine, lustrous and translucent stone", by Xinhua Dictionary published by the Commercial Press.
According to the Encyclopedia of China. "Jade is a natural, beautiful, hard, lustrous and smooth stone, generally referred to as Nephrite and Jadeite", by Encyclopedia of China.
In short, natural minerals which are characterized by their beautiful, hard and smooth features etc. will be named Jade. Under such a wide definition, many different kinds of beautiful stones would be named Jade, so we need to differentiate between Jade and other stones.
Jade Culture in China
Due to its fine, hard, smooth and lustrous features, Jade is personified by five virtues: benevolence, justice, intelligence, courage and purity.
Jade is also symbolic of virtues like beauty, wealth, dignity and incorruptibility etc. Therefore, it is often compared to many matters and objects by scholars, rendering more brilliance to people, objects, matters and views described. Jade played an important role in the development of Chinese civilization. Antique Chinese Jade was not only a vehicle of design, sculpture craft and documentation. It was also prized for its economic value and held importance for ceremonial, religious and ornamental functions. Early during Neolithic times, Jade was processed into ceremonial items and tools. According to Chinese legend, Jade's smooth, fine surface represents mercy; its hard texture symbolic of intelligence; its harmless edges and corners represent justice; and the soul-penetrating sound from the soft knocking on the stone's surface is symbolic of honesty. Jade remains highly prized and over time it has come to personify the spirit and nature of Chinese culture.
The origin of "Feicui" (Jadeite)
According to Shuo Wen Jie Zi, Fei is a type of sparrow with red feathers; Cui is a type of sparrow with green feathers. So in early times, the word Feicui was used to describe small birds with red or green feathers. Later on, a type of mineral was mined and found with both bird-like red and green colors. It was therefore named Feicui. Jaideite is the English term most commonly used to describe Feicui minerals.
Definition of "Feicui"
According to the definition of Regulations of Goods Illustration, Hong Kong, Feicui refers to pure grainy or fibrous polycrystalline aggregates, which mainly consist of either Jadeite, Omphacite, Sodium Chromium Pyroxene, or a mix of all three of them.
Physical Property of Jadeite
Mohs Scale of Hardness: 6.5-7.0
Proportion Value: 3.30-3.36
Refractive Index: 1.666-1.680, Point Assessment: 1.65-1.67.
Colors and Classification of Jadeite
Jadeite contains chromium, iron, manganese etc. Therefore, it reflects a wide color range: white, red, orange, yellow, brown, green, purple and black etc
In the business world there are many types of jadeite. They are categorized by color, foundation and transparency. For foundation and transparency, the varieties can be broadly divided into: Oil green, pea green, hibiscus, gold, Equine dental, etc. In terms of color, the varieties can be broadly divided into: Old deposit, New deposit, Flower green, White- green, Black green, Violet, Red jade, Yellow jade, Purple Jade, Fulushou etc.
Classes of Jadeite: A-Jade, B-Jade, C-Jade and B+C-Jade
A-Jade refers to natural hard Feicui with high density. Normally, Feicui will undergo ash cleaning, fruit-acid-cleaning and warm-sugar-bath (stew wax) processes after polishing. The polished Jade will first be cleaned with charcoal ashes, next be put into plum water with low acidity to remove light black and yellow dots and in the end stewed in vinegar to improve its gloss.
B-Jade refers to Jadeite (Feicui) which undergoes chemical treatment and is injected with resin. Its natural structure has been destroyed or changed, though its color remains natural without dyeing.
C-Jade refers to Jadeite which undergoes a dyeing process to gain a better color.
B+C-Jade will undergo chemical treatment, be injected with resin, and dyed. Its natural structure will either be changed or destroyed.
Among the above four classes, only A-Jade is classified as natural Jadeite, while the other three are human-processed Jadeite.
Counterfeit Jadeite (Imitations of Jadeite)
Imitations which have a Jadeite-like look and are actually taken as Jadeite, are called counterfeit Jadeite. Counterfeit Jadeite can be made out of either natural or synthetic gemstones. Counterfeit Jadeite that is made from natural gemstones can be seen in Chrysoprase (commonly known as Australian Jade), Dyed quartz or Aventurine Jade. Synthetic counterfeit Jadeite can be made from plastic goods or dyed glass.
Authentication of Jadeite
It is difficult to tell with the naked eye the difference between genuine Jadeite and a synthetic version, so it is recommended to purchase gem products carrying the Authentication Certificate of Jadeite.
Tests that will be conducted according to the instruction of the Authentication Certificate
of Jadeite are as follows:
- Sharpness and Cut
- Refractive Index
- Specific Gravity
- Chelsea Color Filter
- Visible Spectrum
- Infrared Spectrum