Moonstone

Moonstone, Labradorite, Amazonite, Sunstone, Spectrolite and Orthoclase are all members of the Feldspar family. Did you know that feldspar is the most abundant mineral in the earth’s crust? Gemstones in the feldspar family are often described as having schiller, opalescent or adularescence. These terms refer to the shimmery effect that appears just below the surface when moved around a light. The feldspar family is split into two groups; Orthoclase e.g. moonstone, amazonite, and plagioclase e.g. labradorite and aventurine. Moonstone is my personal favourite gemstone and it will certainly be found in my engagement ring design!

It is an opalescent variety of orthoclase and has a monoclinic crystal structure, a vitreous lustre and a hardness of 6 on the Mohs’ scale. It has a blue or white schiller which is caused by the alternate layering of albite; thick layers cause a white schiller, thin layers cause a blue schiller. It has a lovely quality known as adularescence, which means the hue and saturation of the blue/white colour will alter as the gemstone is moved around. The Romans believed that moonstone was actually hardened rays from the moon, and its name of course comes from its lunar likeness! In fact most ancient civilisations worshiped some form of lunar god and often used moonstone in rites e.g. the Egyptians worshipped Thoth and Khonsu, whereas the Myans worshipped Ix Chel. Did you know it is also known by the name hecatolite? Moonstone can often have a pitted appearance and can have ‘centipede’ inclusions of parallel cracks caused by strain. Some people (like me!) see the inclusions as an attractive and visually fascinating feature of the stone which shows off the natural, unique, geological aspect of the gemstone… its all a matter of personal preference!

Moonstone is often associated with magic, healing and fertility, and is believed to be a good luck stone which promotes a passionate temperament. Ancient farmers believed that they would help induce healthy heavy yielding crops. In India they believe the gemstone to be a sacred zodiac stone which induces sweet dreams. It apparently helps to create a balance between yin and yang! They are often used in ‘spiritual’ or New Age jewellery and still form a part of basic druid and wiccan rites. Clear moonstones were a fairly popular option in antique British jewellery. It has been a very popular option for jewellery since ancient times and was famously used in the Art Nouveau jewellery of Rene Lalique.

Moonstone is usually mined by hand as they usually are found as masses of rock and pebbles. The most popular method is underground mining. Long, narrow holes 20 to 30 feet deep are dug into the earth in an area conducive to moonstone production. Miners, carrying huge wicker baskets, are lowered into them. They shine flashlights on feldspar veins. Once they see a likely looking vein, the miners follow it with a pick axe. The miners fill the baskets with loose dirt, gravel and pebbles. They then lift the baskets back up above ground, where others wash the loose gravel and pebbles in search of quality gemstones. Moonstone is also found in alluvial deposits which are sieved to pan through river deposits.

Moonstone with a strong blue schiller and inclusion-free clear appearance and good cut are considered the most valuable stones however you can also source stones known as rainbow moonstone, and a variety of colours e.g. brown, peach, green, grey, yellow etc. Stones are sometimes heat treated and can also be dyed. If you are worried about your engagement ring or wedding ring design you certainly won’t be lost for choices! The most desirable blue moonstones have risen in value as they have become rarer. There are some imitations stones on the market; however these tend to be a fairly poor likeness and can be spotted fairly easily. The way a stone is set can have a large effect upon the appearance of the schiller, and some stones on the market are sold with a kind of backing which intensifies the appearance of the schiller.

There are some rare stones which even show a display of chatoyancy or four-rayed asterism! You can source stones from around 1.5mm to 14mm in size depending upon the shape you are searching for. Fine gem quality blue moonstone can be quite rare and difficult to source! You should always take care when wearing moonstones as they can be fairly fragile stones. If you are hoping to wear this lovely gem in jewellery worn everyday such as engagement rings and wedding rings, try to choose a design that will offer the gemstone protection with a secure setting such as a rub-over setting. Moonstones can also make a lovely choice for other pieces of wedding jewellery such as dangly earrings which move in the light to give a beautiful display of colours. The best stones come from former Burma and Sri Lanka, they can however be sourced from Mexico, Poland, India, Germany, Tanzania, the USA, Brazil, Madagascar, and the European Alps.