Opals come in a magnificent range of colours and colour combinations. There are five categories of opal, each with their own distinct range of colours:
White opal ranges from translucent to semi-translucent and features colourful flashes of colour against a white or pale grey background.
Black opal is translucent through to opaque, with a vivid display of colour against a black or dark background.
Fire opal, or Mexican opal, is red, orange, yellow or brown and can be completely transparent or often displays a milky glow. It doesn’t have the traditional play-of-colour of most other opals.
Boulder opal includes the bedrock on which the opal has grown, called matrix, either as a statement feature throughout the face of the opal, or as a background. The opal itself is translucent to opaque, and most commonly blue in colour.
Crystal opal is transparent with sometimes a milky translucency, and shows a clear background with bright, vivid colour flashes.
Where are they mined?
Since the 1980’s Australia has been the world’s number one source for opals, with several famous mining fields producing high quality, unique gemstones. These include the well-known Lightning Ridge, Coober Pedy, Mintabie and Andamooka areas.
Opal is also mined on a smaller scale in Mexico, Brazil, Ethiopia and the USA.
Qualities to look for
Opals vary widely in appearance, with each one displaying completely unique patterns and intensity of colour.
It is this individuality that makes them so special and highly desired. The colour of an opal is an extremely important quality to note, with brighter, more vivid saturation being the most highly prized. Traditionally, reds and oranges are the most desirable colours, however these can change with different fashion trends and of course are dependent on personal preference.
Ideal clarity will vary depending on the kind of opal, for example crystal opals should be transparent with minimal milkiness, whereas the more opaque a black opal, the more valuable it is. This is because these qualities provide the best backdrop for accentuating the flashes of colour, or colour play, within the stone. The patterns that the play of colour produce are also determining quality factors, with larger, more pictorial patterns taking preference over smaller scatterings of colour.
How to wear
Opals are delicate and can be easily scratched and chipped
if knocked, so are best suited for pieces which are worn on special occasions, with a hardness of 5-6.5/10. They work well in necklaces and earrings, as these don’t risk getting knocked and scratched as easily as stones in a ring. Special care needs to be taken to ensure the longevity of opals. See our detailed care instructions here
for more information on how to look after opal jewellery.
What makes them special?
Opals are the birthstone for October.
They are made from 20% trapped water. Opals are formed when arid areas receive high volumes of rain. The rain seeps into the bedrock and later evaporates leaving behind solid silica, which forms the gemstone.
The ancient Greeks and Romans named opal ‘opalus’, meaning “to see colour change”, and believed the gem symbolised love and hope.
Opals in history
The oldest discovered opal relics were located in a cave in Kenya and were believed to have originated from Ethiopia in around 4000 BC.
Hungary was a major historical producer of opal however, due to a decline in natural supply from the late 18th century, no longer mines new material.
Mark Antony is said to have coveted opals, and frequently gifted them to Cleopatra.
Queen Victoria loved opals, and collected and wore them throughout her reign, resulting in their popularity spreading throughout Europe.