Opal and its properties

If you’ve ever seen an opal, it’s easy to understand why this beautiful gemstone has been revered for centuries. The innumerable colour patterns and varying hues of the stone make it one of the most unique gemstones on the market, a quality for which it is highly prized. Keep reading to learn more about this colourful stone and how it has been used since ancient times.  

Colouring and other physical properties

There are many varieties of opal on the market, some of which are fairly common and well-known, and others that people outside the jewellery or mineral industries are likely to be unaware of. Some of the most recognized varieties include black opal, fire opal, hyalite, and white opal. Each of these exhibit different hues and play of colour (the rainbow-like colours that change depending on light or perspective).

Opals are very porous and also quite susceptible to internal and external cracks, with is known as crazing. Some of this can be prevented by storing opals in water, which is a method often employed by jewellers or mineral collectors. Crazing can also occur when an opal is exposed to intense light, or when a stone is allowed to dry too quickly.

Opals throughout history

Opals have been a source of fascination since ancient times. During the height of the Roman Empire, opals were highly valued and served as symbols of hope and love. The ancient Greeks looked to the stones to protect them from diseases and also believed they gave people the gift of prophecy. Other cultures also had opinions on opals, including Arabs who believed the gemstones came from heaven, and Europeans who valued them as representing truth and purity. One common link found across the globe and throughout history is that opals have been considered the luckiest of all gemstones, as well as the most magical because they embody the colours of all other precious stones.

Metaphysical uses

Speaking of luck and magic, opals have also been used over the centuries in a variety of metaphysical ways. Opals have been regarded as healers of depression and having the ability to help its wearer find true love. They are also believed to help stimulate creative thought and originality.

The porous nature of the stone also factors into metaphysical uses, with some believing that the stone’s absorptive abilities can enable the wearer to better pick up the feelings and thoughts of others.

Uses and value

Opal is frequently used in jewellery and cabochons, which are gems that are polished but not cut. It’s also a favourite of mineral collectors, who compete to see whose stones display the brightest and most unusual and brilliant play of colour.

The value of an opal is determined by several key factors: the class of opal, the body colour, the play of colour, and brilliance and pattern. Whether or not the opal suffers from crazing is another important aspect. Black opal is considered the most valuable and can fetch prizes of more than $15,000 per carat.