Moonstone

Moonstone belongs to a large mineral family of feldspars, of which almost two thirds of all rocks on earth consist, and is the most valuable variety of feldspar. It is an opalescent stone, which forms in a range of colours from colourless to blue, peach, pink, green, yellow, brown and grey, with a silvery sheen. The intensity of the body colour is due to varying quantities of iron present within the stone. The iridescent sheen is know as ‘schiller’ which means a colourful play of light. In moonstone, this phenomenon is called ‘adularescence’ and is caused by light rays refracting and scattering inside the stone between lays of albite and orthoclase feldspar. The most desirable moonstone has a blue sheen, with a colourless body colour and perfect clarity.

Another feldspar variety is Rainbow Moonstone. This is labradorite feldspar and its sheen has a variety of rainbow colours. This particular variety has become very popular and is now becoming scarcer. Moonstone has a hardness of 6 on the Mohs' scale and is usually cut as a cabochon to maximize the colour effects within the stone.

Moonstone has been found in the European Alps, near the Adula Group, from where the name ‘adularia’ comes. The most desirable moonstone comes from Sri Lanka, along with the USA, Brazil, Australia, Myanmar and the rainbow variety from Madagascar.

Moonstone is a historically important gemstone and has been valued for centuries, particularly by royalty. It was popular with the Romans who thought that moonstone was formed out of moonlight, hence its name. In ancient Rome, moonstones were believed to change their look during phases of the moon. They also thought that a picture of Diana, goddess of the moon, could be seen in every moonstone. In the Middle Ages, people believed that you could look into a moonstone and fall into a deep sleep that would predict the future. Folklore says that moonstone could awaken tender passions, if placed beneath the tongues of lovers at full moon. Even today, in Arabic countries, women still sew a moonstone, out of sight, into their dresses, as a symbol of fertility. Moonstone was a sacred gemstone in India and is still today. They are regarded as ‘dream stones’ which bring the wearer beautiful visions at night. In East Indian tradition, moonstone represents the symbol of the Third eye and clarifies spiritual understanding.

Moonstone was very popular in the 20th Century and was used in many pieces of Art Nouveau jewellery, particularly by the famous French master goldsmith, Rene Lalique.

Moonstone is one of the birthstones for June and the zodiac sign Cancer (June 21st to July 22nd)