History of Jade
The discovery of the gemstone dates back to the stone age. In New Zealand, jade was used as weapons, fish hooks and farming tools. Thousands of years ago, the Mayans and the Aztecs used jade to heal spiritual and physical illness. It was in China that the carving of jade became a tradition. The Chinese valued the gem so much that it became a status, only the emperor was allowed to own Jade and the most influential members of the society would even be buried in jade. For 9,000 years jade has become a symbol of benevolence, prosperity, purity and health.
Types of Jade
Jade is a term used to identify a variety of gemstones but there are only two pure forms, the Jadeite and the Nephrite. The very first jade discovered in China was the Nephrite. It is composed of calcium magnesium iron silicate. For more than 5,000 years, it was carved into different ornaments, jewelries and religious pieces by Chinese crafters. This type of jade can be distinguished by being less translucent with a resinous lustre. Jade was so revered in China that the demand had caused the deposits to become depleted. In the 18th century, in search for more sources of the gemstone, a tougher, denser and vitreous kind of jade was discovered in the neighbouring country, Myanmar (Burma). The Jadeite is a sodium aluminum silicate mineral. It is glassy and has a very smooth texture ideal for making jewellery and traditional collector’s pieces. Today, it is the preferred kind and it has acquired more value. It is from Myanmar that the rarest and purest jade was found, the Imperial Jade. It is sold for the same price per carat as diamonds in the United States.
Most of the jadeite can be found in northern Myanmar but small amounts are mined in Russia, Guatemala and Mexico. Since 2014, 75% of the world’s nephrites come from British Columbia. The rest are from New Zealand, Australia, United States and Japan.
Jade can be distinguished from other gemstones by its hardness and density. The jade item should be cool to touch, has a soapy feel and is heavier than it seems. Due to its density, the jade produces a deep sound when struck, compared to that of a glass. The best method to identify jade is to measure its specific gravity by dividing its weight in grams by its volume in ml or cc. The jadeite should have the density of 3.20- 3.38 and the nephrite 2.90- 3.03. When placed under a magnifying glass or microscope, microcrystal fibers should be evident in an authentic jade. The nephrite has a loose interwoven fiber structure which causes it to splinter when fractured. Whereas the Jadeite has a much more compact fiber structure which makes it extra tough. You can also do a scratch test, a real jade will be able to scratch through glass. Due to its structure, jadeite is identified to be tougher than diamonds. Common colors for the jade are green, lavender, yellow, orange, white, grey and black. It ranges from being translucent to opaque. Each piece of jade is unique. It comes in different shapes and sizes and may have impurities and grains which gives its character.
Categories of Jade
Type A – are items which have only undergone traditional treatments. It is washed in plum juice and polished with beeswax. This type shows the 100% natural color of the jade.
Type B – this category uses bleach to remove brown impurities. Polymers are used to fill in the gaps caused by bleaching, this makes the jade tougher and improve its clarity but discolouration may occur overtime. Nevertheless, authentic jade is used.
Type C – the jade is placed under high heat to absorb artificial colouring and bleaching to remove impurities. It is then impregnated with polymers to make it strong. Discolouration occurs overtime as the artificial solutions breakdown with sunlight, body heat and cleaning agents. You can identify this type of jade by using a magnifying glass to examine the cracks. If the colour is darker around the cracks it is evidence that the jade piece has been acid washed and dyed.
All these types use real jade but the value of the item decreases the more “beautification” process it undergoes.