Australia is renowned for producing some of the most exquisite opals in the world. Whether you're a first-time buyer or a seasoned collector, understanding the unique characteristics and varieties of Australian opals can help you make an informed purchase. Here's everything you need to know before adding these stunning gemstones to your collection.
Opals' Unique Play-of-Colour
Unlike other gemstones that derive their colour from transition, opals are prized for their play-of-colour. This phenomenon occurs due to the diffraction of light by the tiny silica spheres within the stone. Larger spheres can produce the full spectrum of colours, while smaller ones may only show blues and greens. Opals with predominant red hues are exceptionally rare and highly sought after.
Types of Australian Opals
1. Black Opals
Black opals are the most valuable and rarest type, featuring a dark background that enhances their vibrant colours. These opals are predominantly found in Lightning Ridge and New South Wales.
2. White Opals
These opals have a lighter, milky background with soft, pastel colours. Coober Pedy in South Australia is the main source of white opals, making it a popular destination for opal enthusiasts.
3. Boulder Opals
Boulder opals are unique because they are cut with the host rock (usually ironstone) on the back. This variety is known for its durability and striking patterns, typically mined in Queensland.
4. Matrix Opals
Matrix opals have opal material interspersed within the host rock, resulting in a fascinating blend of colours and textures. These are often found in Andamooka, South Australia.
Classic Jewellers - Aurora Octopus Opal Pendant
Key Factors to Consider When Buying Opal Jewellery
Colour and Play-of-Colour
The most critical factor in determining an opal's value is its play-of-colour. Look for stones with a broad range of bright, intense colours. Black opals with a dominant red play-of-colour are particularly valuable.
Pattern
The pattern of the play-of-colour also influences an opal's value. Desirable patterns include harlequin, floral, and pinfire. Each pattern is unique, adding to the stone's allure.
Transparency
Opals can range from opaque to transparent. Crystal opals, which are semi-transparent, can exhibit a vivid play-of-colour and are highly prized.
Cut
Opals are typically cut into cabochons (a smooth, rounded, and polished shape) to maximize their play-of-colour. The best cuts enhance the stone's natural beauty without compromising its integrity.
Size
While larger opals can be more valuable, the quality of the play-of-colour is more important. A smaller opal with vibrant colours can be worth more than a larger, duller stone.
Classic Jewellers - Daisey Doublet Opal Ring
Historical and Cultural Significance
Opals have been treasured for centuries, with artifacts dating back thousands of years. The Romans prized them as early as 250 BC, and they hold a special place in Australian Aboriginal Dreamtime stories. Since the late 1800s, Australian opals have gained international recognition, and today, Australia is the world's leading producer of precious opals.
Purchasing Tips
Consider Custom Designs
Because each opal is unique, custom jewellery designs can highlight the stone's individual beauty. Many jewellers offer bespoke services to create personalised pieces that showcase your opal's distinctive characteristics.
Maintenance and Care
Opals are relatively soft compared to other gemstones, with a hardness of 5.5-6 on the Mohs scale. To keep your opal jewellery looking its best:
- Avoid exposing it to harsh chemicals or extreme temperatures.
- Store it separately to prevent scratches.
- Clean it gently with a soft cloth and mild soapy water.
Australian opals are a stunning and unique addition to any jewellery collection. By understanding their unique characteristics and knowing what to look for, you can find a piece that is not only beautiful but also holds significant value. Whether you're drawn to the vibrant hues of a black opal or the delicate play-of-color in a white opal, these gems are sure to captivate and enchant.
