LEARN ABOUT OPALS
Opal formation
Opal was formed during the Cretaceous period between 65 -140 million years ago, in an inland sea called The Great Australian Basin. It occurs to a depth of around 90 feet (30 metres) underground, in veins of about 3 feet (1 metre) called “The Opal Level”. There may be up to 5 Opal levels down to 90 feet. The formation consists of mainly silica, with the colour coming from the refraction of light off the microscopic silica particles.
Opals are valued on their foreground colour, brightness and pattern. This process applies to all types of Opal.
Brightness - This is the most important aspect of Opal valuation. The brighter and stronger the better!
Colour - Blue is the most common colour, then Green and Orange, Red is the rarest and most valuable colour.
Pattern - The most common and least valuable type of pattern is pinfire, the larger the splash of colour the better. Other patterns include ribbon, Chinese Writing and Harlequin, which is the most prized pattern.
See Opal Types
Opal Valuation
Opals are valued on their foreground colour, brightness and pattern. This process applies to all types of Opal.
Brightness - This is the most important aspect of Opal valuation. The brighter and stronger the better!
Colour - Blue is the most common colour, then Green and Orange, Red is the rarest and most valuable colour.
Pattern - The most common and least valuable type of pattern is pinfire, the larger the splash of colour the better. Other patterns include ribbon, Chinese Writing and Harlequin, which is the most prized pattern.
Opal Myths
Around 130 years ago, to try and protect their market, English diamond merchants started many blatant lies that have been perpetuated.
The truth is: Opal is hard - it is the same hardness as glass.
Opal is lucky - for centuries before this myth emerged, Opal had been considered to be a stone of good fortune.
Opal does not lose its colour or brightness in sunlight and is not affected by water.