Learn about the kaleidoscopic gem and discover our favourite opal jewellery creations.
Because of its extraordinary play-of-colour, the Romans thought opal was the most precious and powerful of all stones. The ancient Greeks believed opals gave their owners the gift of prophecy and preserve from disease and Arabic legends say that opals fell from the sky during thunderstorms and contain lightning.
- Name : From the latin opalus, synonymus with “precious stone”
- Mineral: Hydrated Silica
- Colour: All the colours of the rainbow
- Mohs Hardness: 5 to 6.5
- Symbol : Love, hope, purity and truth
- Birthstone: October
Play-of-colour: Opal is known for its unique display of flashing rainbow colors called play-of-colour that makes it unlike any other gem : in 75 AD, the Roman Pliny observed, “Some opali carry such a play within them that they equal the deepest and richest colors of painters.” Play-of-color occurs in gem opal because it’s made up of tiny spheres of silica. As the lightwaves travel between the spheres, the waves diffract, or bend. As they bend, they break up into the colors of the rainbow, called spectral colors.
- White opal with play-of-color against a white or light gray background color, called bodycolour
- Black opal with play-of-color against a dark bodycolour
- Fire opal with brown, yellow, orange, or red bodycolour but no play-of-colour
- Boulder opal with play-of-color against a light to dark bodycolour. On boulder opal, fragments of the surrounding rock, called matrix, has become part of the finished gem.
- Crystal or water opal: showing exceptional play-of-color on a clear background
Where it’s found: When Australia’s mines began to produce opals commercially in the 1890s, it quickly became the world’s primary source for this October birthstone. Opal can be found otherwise in Ethiopia, South America (Brazil, Peru and Mexico) and Nevada.
Quality factors : Play-of-color, intensity, and pattern are the most important value factors.
Precautions: Opal contains up to 20% of water in its internal structure, which makes it sensitive to heat, excessive dryness or direct exposure to bright light. If an opal loses moisture, it develops fine cracks spoiling the beauty of the gem. Opal is also fragile: opal cabochons are thick enough to withstand everyday wear but thinner pieces make it more vulnerable to break.
WHY WE LOVE THAT STONE
Formation : Opal is a rainbow trap inside a rock
Play of colours : Even today, opal invokes a feeling of magic and mystery
Unique: Opal’s array of silica spheres form a fantastic variety of patterns and colours, and no two opals are exactly alike.
FAMOUS OPALS STORIES
The Fire Queen: The black opal of nearly 900 carats has an interesting and somewhat sad story. Found roughly around 1906 in the Angledool diggings the Fire Queen was originally named ‘Dunstans’s Stone’ after its finder Charlie Dunstan. It was alive with colour and dubbed too beautiful for words – truly a unique piece. After selling it for a mere £100, as there was hardly any market for big black opals in those days and being, Charlie was found with two gunshot in his head. The stone only reappears in 1928 valued at £40,000 at the Chicago Museum. In the 1940’s, it was then resold to J.D. Rockefeller for £75,000, who donated her to his prestigious family collection.
Marcus Antonius & Cleopatra: Plinus writes about Nonius, a senator of the Roman republic who owned a fabulous opal ring. Marcus Antonius was so fascinated by the stone that he started to covet it for his lover Cleopatra. And as Nonius turned his offer to buy it, he simply banished him out of Rome and deprived him from all his belongings as a desperate attempt to put his hands on the precious ring.
The Royal One: The 306-carat, gem-quality black opal was on sale in 2013 for $3 millions. The last significant black opal was the Aurora Australis, found in 1938, only half its size and valued at $1 million in 2005.
FAVOURITE OPAL JEWELLERY CREATIONS
With its colour palette, opal brings its mystery and beauty to jewellery. Discover our favourite opal creations :