From time immemorial, jade has been closely associated with the Chinese culture. To the Chinese people, it has the power to protect body and spirit for both the living and the deceased; they also treat it as talisman. In the West, jade is sought after for its elegance, mystique and romance.

Jade can be classified into two different types, nephrite and jadeite. They are two totally different minerals. Colours of nephrite include translucent white, yellow, green, black and the colour is always evenly distributed. Colours of jadeite include white, purple, yellow, green and others; evenness of colours varies with different textures.

Most of the jades yielded in China are nephrite. Among highly treasured pieces of nephrite are some described as "mutton fat". As the description implies, these are pieces creamy white in colour and uniformly translucent. The majority of fine-carved jade artifacts are made of nephrite.

Jadeite is mainly produced in Burma.Since it is more prominent than nephrite in different aspects, such as texture, colour and price, it is used almost exclusively in jewellery setting, which also lead to a large demand in the market, so we will confine our discussion to jadeite.

Jadeite is also known as fei tsui. The criteria we employ for its appreciation are : colour, transparency, clarity, cutting and flaws.

COLOUR

Colour is of paramount importance. We examine the colour of fei tsui according to the following criteria:

1. Purity

Purity refers to the proportion of the prime and the secondary colours. Let's take green fei tsui as example, the most desirable is pure green; in descending order of desirability are green tinted with yellow, blue and grey.

2. Intensity

The more saturated the green the better the jade. However, an overdone intensity is of only middling quality.

3. Vividness

The colour should be vibrant and lively. The presence of grey and black makes the green dull without altering its tint.

4. Evenness

The more even the colour, the more desirable the jade and the higher the value.

TRANSPARENCY

Transparency of fei tsui affects the refraction of light and its beauty. When light enters a transparent fei tsui with fine texture, it sparkles; if light enters an opaque fei tsui with coarse texture, it refracts dull light to the eye that reduces attractiveness.

CLARITY

Clarity refers to inclusions, which cohered with jade during the formation process, mainly in black and white. In general, white inclusions are less distracting than black ones and, of course, the less visible the inclusion the better.

CUTTING

Fei tsui is usually worked into two categories: plain polished shapes such as cabochon and carved designs. Plain polished shapes require higher grade material without flaws, and with good proportion, symmetry as well as appropriate thickness. For example, a well-cut cabochon should be neither too thick nor too thin in relation to the area of its top surface. Its "bulge" should be centered, prominent but not exaggerated.

Carved designs are often used to eliminate or minimize the effect of flaws and cracks. They are assessed on their aesthetics and the workmanship of the details.

FLAWS

Flaw lines are value-detractor of fei tsui.Fei tsui can be cracked and even broken when crashed. We can use a torch to examine cracks and flaws, so consumer should pay special attention when making purchase.

High quality jade can be sold at desirable price, however, it has a limited supply. To maximize profit, some businessmen proceed artificial treatment to jade before putting them on the market. Jade is then categorized into "A" jade, "B" jade and "C" jade.

Treated Jade

"C" Jade

"C" jade is dyed jade. During the treatment process, dyes are injected to colourless jade under a high temperature and high pressure environment. The jade will be wholly or partly be dyed into green or purple colours, however, by and by the colour of "C" jade will become dull and fade.

"B" Jade

The treatment process of "B" jade involves removing inclusions and impurities near the surface by bleaching or other chemical means, leaving mainly green and white material. Polymer resin, a chemical that solidifies into an almost colourless, clear mass, is then injected into the stone to fill up leftover space and enhance translucency. Since the structural integrity of jade is damaged during the process, flaws will appear very easily. If dye is injected during this treatment process, it can be categorized as "B + C" jade.