What Do You Know About Opals And Opal Jewelry?

Many people are fascinated by and love the exquisite gemstones called opals. Opals come in many different shapes and sizes and the colours can vary from pale, milky whites with delicate internal colours of pale blue and primrose yellow through to vivid blue, green and black opals that flash red, gold, blue and green fire. These gemstones are a mineraloid gel, so they do not have the same structure as crystals. They are formed from a mixture of water and silicon dioxide. Over a very long period of time, water flowing through through the ground picks up silica from sandstone and washes it into crevices and cracks in the rocks. The moisture then slowly evaporates leaving behind a deposit of silica, and as the cycle is repeated the opal slowly begins to form. Opal can also form over fossils locked into the rocks, creating vividly coloured gemstone depictions of long extinct creatures. One of the most famous opalised fossils in the world is in the National Opal Collection in Sydney, Australia, and is a 2.7 metres long pliosaur who has been nicknamed ‘Nessie’. There are also Boulder opals which form in fissures and cracks within ironstone boulders. These Boulder opals are very colourful and have a natural layer of ironstone on the back. This layer of ironstone is left intact by the opal cutter as this layer is needed to be able to cut a decent size stone that exhibits all the delicate veins of colour.

Opals are generally valued by their size, body tone, colour, brilliance and quality, with black opals being the most valuable followed by the Boulder opals and then the milky, pale opals. How the gemstone is cut and polished also partly determines the value of the stone. On examination, an opal is given a price ‘per carat’ and how much you have to pay for your gemstone will depend on its carat size. Body tone is one of the most important things in determining the value of an opal. Body tone in an opal is the background colour of the gemstone which ranges from black, through dark, to light. Generally the darker the body tone, the more valuable the stone, as dark backgrounds are better canvasses for showing off all the wonderful, flashing colours that an opal can contain. The pattern of the colours is unique to each individual opal, and some of the most sought after patterns are Ribbon, Straw, Harlequin, Picture Stones, Flagstone and Chinese Writing.

Opal doublets and triplets are opals that are not all natural gemstone, but have had black backings glued onto to them, so that they resemble a black opal. The black backings can be made of various materials such as plastic, black potch, brown ironstone, or black industrial glass. A doublet is simply a slice of precious opal glued to the dark backing, with the backing designed to bring out and enhance the colour in the gemstone. A triplet has the opal stuck to the dark backing with a layer of quartz, clear glass or plastic forming a dome over the gemstone. Opal doublets and triplets are not nearly as valuable as solid opal, with a doublet being more valuable than a triplet, as a triplet generally only contains a very thin slice of real precious opal. The clear cap on the triplet does tend to make it fairly simple to identify it as not being a solid stone, as they generally have a glazed appearance and, if you look at the side of the stone, you may be able to see a line where all of the layers meet. The plus point of a triplet is that the top clear layer makes the stone more resilient than solid opals or doublets, so if you want to wear an opal frequently or find a piece of opal jewelry for a child to wear, then a triplet might be just what you are looking for. They are also much cheaper, so can be worn as casual costume jewelry or given as a small gift to a friend or a loved one.

Opal is Australia’s national gemstone and around 97% of the world’s opals are mined in Australia, with 60% of the Australian opal output being white opals, 30% crystal opals, 8% black opal and around 2% being Boulder opals. Black opals are mainly found around Lightening Ridge in New South Wales and Andamooka in South Australia. Coober Pedy, also in South Australia, is known as the ‘Opal Capital of the World’ and about 70% of the world’s precious opal is mined in an area that covers 4954 square kilometres. Boulder opals come from Western Queensland, and the rarest of all the Australian opals, the pipe opal, comes from the area surrounding Jundah. Pipe opals are very similar to Boulder opals, but they form in sandstone that generally contains fossilised tree roots that adds iron-ore content. Opals are also mined in the United States, and black, white, crystal, lemon and fire opals are found in the Virgin Valley opal fields of Nevada, and the black fire opal is Nevada’s official gemstone. White opal is also mined in Idaho, around the town of Spencer. In Europe, the gemstone is mined in Slovakia, the Czech Republic, Hungary and Turkey. There are also deposits in Brazil, Nicaragua, Ethiopia, Honduras and Guatemala. Mexico is famous for producing fire opals, which are translucent gemstones containing vibrant body colours such as reds, yellows and oranges. However, these stones very rarely exhibit any of the play-of-colour that you see in the other opals. There are also very pretty Peruvian opals, which are blue-green gemstones that range from semi-opaque to opaque.

During the Middle Ages in Europe, opals were regarded as being very lucky gemstones because they contained so many different colours. It was thought that because the opal contained all these colours, it also had all the attributes of the other gemstones, so an opal potentially had all the virtues of a ruby, emerald, sapphire, turquoise or amethyst all contained within the one stone. It was also believed that if you wrapped an opal in a bay leaf and held it in your hand that you would become invisible. They also had a reputation for being an unlucky gemstone, but this could be due to the fact that opals are fairly fragile. Black opals were thought to be used by witches to increase the power of their magic, and they were thought to resemble ‘The Evil Eye’. Their reputation as being a bringer of bad luck grew after the publication of Sir Walter Scott’s novel ‘Anne of Geierstein’ in 1829, where one of the characters wears an opal amulet imbued with supernatural power. During the story this beautiful gemstone totally loses its colour and lustre after being splashed with holy water and the character dies shortly afterwards. Opals are the birthstone for the month of October and the zodiac sign of Libra so would make a wonderful birthday gift for your Libran friends and family.

Opals are not the most robust of gemstones, only being about as hard as glass. Therefore, your opal jewelry should not be worn if you are planning on doing any manual labour or strenuous outdoor activity. Some people believe that opals will crack if they are not occasionally soaked in water, but despite their high water content, they are hard and so will not absorb any water. In fact opal doublets and triplets should never be immersed in water, as the water may damage the glue and cause the layers to separate. The same goes for polishing your opals with olive oil; none of the oil will be absorbed so there is little point. You may need to take your solid opals to be professionally polished after a number of years to regain their lustre, but you should never put them into an ultrasonic cleaner as this may cause them to crack.

So if you want to add a beautiful and unique opal to your jewelry collection, you will be pleased to know that there is a wide range of opal jewelry available online. Amazon has a really impressive range, so why not have a look if you searching for a jewelry gift or treating yourself? You will find opal bracelets, pendants, earrings, rings and necklaces to suit all tastes and budgets. Choose from black, blue, white and fire opals. You are bound to find the perfect piece of opal jewelry for you, and be able to revel in having all of the luck, protection and healing of many gemstones contained with the colours of one beautiful gemstone.

Copyright 2010 CMHypno on HubPages