Thinking about using opal in your next jewellery creation? Read on to learn what opal is, how to care for opal gemstones and more, with Cooksongold.
What is opal?
Opal is a non-crystalline substance quite unlike other gemstones. It is composed of hardened silica gel which occurs naturally, as well as being a widely used man-made product used in many household cleaning products. Many people consider Opals to be unlucky but this has more to do with their fragility than anything else. Opals contain between 5 and 10% water which means that they are prone to drying out and eventual cracking so they must be treated extremely carefully. Opal stones are also very soft, measuring only a 6 on Mohs scale of hardness which makes them unsuitable for certain types of jewellery.
What are the different types of Opals?
Opal gemstones are the most fascinating and revered of stones due to their unparalleled flashes of rainbow colour which are quite unique. There are basically two types of opals:
- Precious Opal – displays the iridescent flashes of colour
- Common or ‘Potch’ Opal – often opaque and has no iridescence.
The more effective the diffraction, the brighter the play of colours will be. Thus, the more desirable and valuable the stone, so that is the most important element to focus on when choosing an opal. This amazing effect is created due to the internal structure of the stone which forms as a series of spherical silica particles.
In simple terms, it’s the way these particles align which causes light to behave in the way it does; causing the most beautiful diffraction of rainbow colours.
Due to their delicate make up, Opals are not generally suitable for faceting and in the main are usually cabochon cut. They are sold either as a solid opal or as doublets or even triplets which all have distinct differences which affect the value of the stone:
Solid Opal: A solid stone consisting solely of Opal.
Opal Doublet: Consists of a thin layer of precious Opal backed by a layer of darker material (usually Potch Opal, Obsidian, Onyx or Ironstone). The dark backing enhances the play of colour thereby improving the look of the stone.
Opal Triplet: Contains a dark backing similar to a doublet but also a third clear top layer to protect the Opal usually made from plastic or clear quartz. The clear layer magnifies the colours of the Opal whilst the dark backing enhances them; however these stones are not classed as ‘precious’ and often look artificial making them the least valuable of the three.
Opal gemstones come in a variety of colours, including black and blue. It’s a common thought to think of the milky white variety when envisaging an Opal. But some of the most valuable are actually black in colour. Usually originating from Australia (the richest source of Opal), the Black Opal displays a natural dark background illuminating the brighter flashes to great effect. They can often look so amazing that you would be forgiven for thinking it’s a manmade phenomenon rather than a natural one!
Black Opal and Fire Opal
What’s the fire Opal gemstone?
The Fire Opal gemstone contains none of the characteristics of more standard opals whilst being made from essentially the same material. Bright orange in colour, good quality Fire Opal gemstones are transparent and outwardly appear much more gem-like.
Taking care of Opal gemstones
The most important thing to remember when using or buying Opal stones is to treat them with care. Don’t expose them to heat as this will cause them to crack and ensure they are kept well protected from anything likely to cause a scratch or bump.
Doublets and triplets should not be immersed in water as over time this will cause deterioration of the glue bonding the layers together; however solid opals will not sustain any damage from water which is a common misconception.
Harsh cleaning products are to be avoided however as are ultrasonic cleaners which again may cause cracking. There is really nothing too arduous about caring for Opals; it’s really just a matter of common sense which will ensure the longevity of these beautiful stones.
Thinking about including an Opal gemstone in your next design? Take a look at Cooksongold’s full range of Opal gemstones on our website.
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