Opals are a beautiful gemstone that flash an iridescent range of colours and make stunning jewellery!
Opal is really special to Australians, as it is our national gemstone and Australia is where 95% of the world’s opal originates from (that's a lot of opal!)
If you are purchasing opal jewellery, you are likely placing your money back in the Australian economy and supporting local Australian mines.
As we all know, it is more important now than ever before to support local and spend consciously.
Millions of Years in the Making
One of the many reasons you should treasure your opal jewellery is it takes 5 to 6 million years for just 1 centimetre of opal to form!
Natural elements cause stones (eg. sandstones, mudstones etc.) to weather and release silica. This silica is swept up by rainfall or released directly into ground water.
This water, combined with silica, penetrates deep into the Earth via small cracks, faults and joints. It continues to travel downwards until barriers between sandstones and rocks trap the water and silica.
The majority of the water evaporates leaving a silica deposit. The substance then hardens into a gel and eventually, over millions of years, a unique and wonderful opal is formed.
Australia is the main source of opals due to 1/3 of the continent being covered by the sea and having a sedimentary basin millions of years ago. The sea subsided and left large silica deposits deep in the ground.
There are three main considerations for opal quality: colour, pattern and clarity.
An opal is made up of small spheres of silica arranged in a rectangular pattern, with tiny amounts of water between the spheres. In a process called ‘opalescence’, the water and spheres diffract white light, causing the stunning play of colours.
The size of the spheres of silica determines the play of colour in the opal. For example, red in an opal is caused by a larger silica sphere and is rarer and more valuable than blue in an opal which is caused by a smaller silica sphere.
The base colour of the opal also affects its value; a darker base is often more valuable than a white or translucent base as it displays colours more vibrantly.
The size and location of the colour bar (a layer exhibiting a play of colour) affects the opals desirability. This colour bar can be viewed from looking at the opal on its side and the higher and thicker it is, the more vibrant the colours are. The clarity of the colours viewed top down also affects its value – the clearer the better.
Opals can display many beautiful types of patterns and each pattern has a different value based on its rarity.
These can include rolling flashes (large section of colour which rolls across the opal), pinfire (specks of colour), broad flash (large sections that flash as the opal is turned) and many more.
An opal is likely to be more valuable if it is a vibrant, distinct or clear pattern. Patterns can be determined by comparing the opal to relevant opal charts.
Ultimately, beauty is in the eye of the beholder and you are the one who needs to love it - if you think an opal is beautiful, choose it!
In Australia, opal mining is strictly regulated to ensure environmental protection. For example, in NSW, where our Lightning Ridge opals are mined, there is legislation requiring the mineral claim holder to, ‘progressively rehabilitate operations on the mineral claim area’.
There are regulations aimed to protect Indigenous culture, rehabilitate land, revegetate, remove waste and to protect natural water, drainage lines and soil nutrients.
Coober Pedy is known as the ‘opal capital of the world’ and is famous for white opals.
The small mining town ‘Coober Pedy’ is named after the Indigenous phrase, ‘kupa piti’ meaning ‘whitefella’s hole’. It is in South Australia on the edge of the Great Victoria Desert.
Due to the extreme heat, many local residents live in ‘dugouts’ which are excavated caves on hillsides adapted into a home.
Coober Pedy is where we source our white opals (pictured here!)
Lightning ridge is in the outback of New South Wales and is famous for having the largest source of rare black opal.
The way in which Lightning Ridge received its name is slightly dark (just like black opal). It was named after the discovery of a shepherd, dog and 200 sheep were located struck by lightning on a ridge.
We also source opals from Lightning Ridge (pictured here!)
I hope this blog has encouraged you to choose and treasure opal jewellery for its rich history and unique beauty!