Jade, the hip-stone

Jade is the overarching name for two different mineral species: nephrite and jadeite. Until 1863, no previous distinction had been made between them, despite the fact that they share no relation but appearance. The jadeite variety is rarer and thus more precious and highly sought after.

Nephrite jade is found in many places around the world, but appears so abundantly in the Sayan Mountains in New Zealand that it is often referred to as New Zealand jade. In contrast, Jadeite is found primarily in Myanmar with small quantities discovered in Guatemala, California (USA), China and Russia.

Varying in colour, nephrite jade ranges from deep green as the presence of iron over magnesium increases, to a buff colour (more magnesium than iron). Such cream-coloured specimens are often known by the unfortunate name of ‘mutton fat’ jade. Where the iron content in nephrite jade has become oxidised, the stone comes in shades of brown.

The limited colour spectrum of nephrite pales in comparison with the myriad of hues represented by the jadeite variety. With examples cited in pink, brown, red, orange, yellow, mauve, blue, violet black and white, jadeite offers a stone to represent every colour of the rainbow. It is the green translucent jadeite that is the most precious.

The word ‘jade’ is of Spanish origin, derived from the word piedra de hijada, meaning ‘hip stone’. When Spanish explorers brought pieces of the mineral from their travels in India, they decided that the stones looked like kidneys and would thus be useful in aiding diseases of the organ. The French shortened the Spanish name to ejade.

In addition to its fabled connection with the kidneys, jade has been assigned many other healing properties. It is said to aid in blood purification, bone problems, chest and lung ailments, asthma and heartburn. Purple jade with yellow specks was said to resemble a liver penetrated with bile and was believed to heal that organ and related bilious disorders. Dark red jade was used to stop the flow of blood when applied to deep wounds.

Jade is symbolically important in Asia and has featured in many ancient legends. It is said that the Empress of China once ordered all jadeite to be surrendered to the royal collection. So vast was the amount that she required 300 ivory cabinets to house them. This explains why it is called ‘imperial jade’.

Historically, jade has been used in the manufacture of tools, weapons and ritual ornaments by indigenous tribes in China, North America, Mexico and New Zealand. It is surprising to note that nephrite, a densely woven crystal aggregate comprised of calcium, magnesium and iron silicate, has a hardness rating of only 6.5 on Moh’s scale. Jadeite rates a slightly harder 7.

Jade is often cut into cabochons and featured in beaded necklaces, drop earrings and rings. Jade pendants carved into hollow discs (called ‘pi’) are popular, and jade bangles are worn to grant wearers immunity to illness.