The birthstone for October is the opal – and what an extraordinary stone of infinite variety this is.
What is an opal?
The national stone of Australia, the opal is a form of silica and can contain anywhere from 6 to 21 per cent water, by weight. It is formed by being deposited in the fissures of almost any kind of rock, at relatively low temperatures. Some opals, known as wood opals, are in fact formed from deposits that have sunk into trees laid down in prehistoric times. These are rare and simply stunning stones from which jewellery of astonishing beauty can be made. as you can see here!
The most common form of precious opal is the white opal. This type of opal increases in value the greater the play of fire within, in vibrant shades of green, blue, orange and pink. The rarest is the black opal, a dark hued stone from which the flashes of fiery colour spring most dramatically.
How to choose the right opal
Take care when buying opals that you know what you are getting. For use in fine jewellery, most opals are cut and polished as cabochon stones, oval or round with a soft curve rather than facets. ‘Solid’ opal refers to polished stones that consist completely of opal. Opals too thin to produce a ‘solid’, or too milky to throw much fire, may be combined with other materials to form a pretty gem for use in fashion or costume jewellery: an opal ‘doublet’ is made from a relatively thin layer of opal, set on top of a layer of a dark-coloured mineral, most commonly ironstone, dark ‘common opal’ (called potch, by opal miners, which shows no play of colour) or obsidian. The dark backing emphasizes any play of colour in the top stone. An opal triplet is similar to a doublet, but has a third layer, a domed cap of clear quartz or even plastic on the top. The top layer works to magnify the colour play of the opal beneath. Pretty, but not precious.
Why is the opal seen as unlucky?
The myth that the opal is an unlucky gemstone is just that – a myth. Utter nonsense in fact! This myth came about due solely to a novel by Sir Walter Scott. In Scott’s story, the Baroness of Arnheim wears an opal with supernatural powers. When a drop of holy water falls on it, the opal turns into a colourless stone and the Baroness dies. Not such a lucky magic stone for her! Due to the popularity of Scott’s novel people soon began to associate opals with bad luck and death. Within a year of the publishing of Scott’s novel in 1829, the sale of opals in Europe dropped by 50%. Ouch!
Oh how we wish we’d been around then to pick up some lovely bargains!
Today, the opal is chosen by those seeking to make something quite extraordinary and a real talking point – and we’re happy to oblige!