Types of Australian Opals

The Four Main Types of Solid Australian Opal and Two Types of Composite Stones

 

Australian opal is globally recognised for its exceptional quality, vibrant play-of-colour, and long-term durability. When buying opal, it is important to understand the difference between solid opal and composite stones. Below is a detailed explanation of the four main types of solid Australian opal and the two types of composite opal stones commonly used in jewellery.

The Four Main Types of Solid Australian Opal

Solid opal is a single, natural piece of opal cut and polished without artificial backing or caps. These stones are the most valuable and desirable form of opal, especially when sourced from Australia.

1. Black Opal

The Rarest and Most Valuable Australian Opal

Black opal is the most prized opal in the world and is primarily mined in Lightning Ridge, New South Wales. Its naturally dark body tone allows colours to appear more vivid and intense.

Key Characteristics:

  • Dark body colour ranging from charcoal to jet black

  • Exceptional colour brightness and contrast

  • Displays strong reds, blues, greens, and multicolour patterns

  • Extremely rare and highly collectible

Why It’s Valuable:
The dark background enhances the play-of-colour, making black opal the most dramatic and valuable of all opals.

Best for: High-end rings, investment pieces, heirloom jewellery

2. Boulder Opal

Naturally Backed, Uniquely Australian

Boulder opal is mined mainly in Queensland and forms within ironstone boulders. The opal remains attached to its natural host rock, creating bold and earthy patterns.

Key Characteristics:

  • Naturally bonded to ironstone

  • Rich, vibrant colours

  • Each stone is one-of-a-kind

  • Extremely durable due to ironstone backing

Why It’s Special:
Unlike composite stones, boulder opal is 100% natural and considered solid opal despite having a backing — because it formed naturally in the rock.

Best for: Statement jewellery, men’s jewellery, contemporary designs

3. White Opal

Australia’s Most Well-Known Opal

White opal is primarily mined in Coober Pedy, South Australia, and is the most abundant form of Australian precious opal.

Key Characteristics:

  • Light or milky body tone

  • Bright flashes of colour

  • Softer contrast than black opal

  • Excellent affordability compared to rarer types

Why It’s Popular:
White opal offers classic opal beauty at a more accessible price while maintaining stability and natural origin.

Best for: Everyday jewellery, earrings, pendants, gifts

4. Crystal Opal

Transparent with Incredible Depth

Crystal opal is semi-transparent to transparent, allowing light to pass through the stone and enhance its colour display. It can occur in both light and dark body tones.

Key Characteristics:

  • Clear to translucent body

  • Strong play-of-colour with depth

  • Can rival black opal in brilliance

  • Rare high-quality stones command premium prices

Why It’s Unique:
Crystal opal creates a glowing, three-dimensional colour effect not seen in opaque stones.

Best for: Fine jewellery, showcase pieces, collectors

The Two Types of Composite Opal Stones

Composite opals are stones made by combining natural opal with other materials to enhance appearance or durability. While they contain genuine opal, they are not solid opal.

 

Why Choose Opal Doublets?

Opal doublets consist of a genuine opal layer bonded to a dark backing, which naturally enhances the stone’s play-of-colour.

Key Advantages of Opal Doublets

  • Brighter, More Vibrant Colour
    The dark backing intensifies colour flashes, making the opal appear more vivid and eye-catching.

  • Genuine Opal at a Lower Price
    Doublets use real opal, allowing customers to enjoy authentic opal jewellery without the high cost of thick solid stones.

  • Excellent Visual Size
    Because the opal layer is thinner, doublets can be cut into larger face-up stones, creating bold designs without excessive weight.

  • More Stable Than Many Overseas Solid Opals
    Australian opal doublets are generally more stable than high-water-content opals from some other countries.

  • Ideal for Everyday Jewellery Designs
    When properly set and cared for, doublets perform very well in earrings, pendants, and necklaces.

Why Choose Opal Triplets?

Opal triplets are made from three layers: a natural opal slice, a dark backing, and a clear protective cap (usually quartz or glass). This construction offers unique advantages that many buyers appreciate.

Key Advantages of Opal Triplets

  • Striking, High-Impact Colour
    The clear top layer acts like a lens, magnifying the opal’s play-of-colour and giving the stone a bright, lively appearance.

  • Added Surface Protection
    The protective cap helps shield the opal from scratches and minor impacts, making triplets particularly practical for jewellery.

  • Exceptional Value for Money
    Triplets allow customers to enjoy the look of premium opal jewellery at a fraction of the price of solid opals.

  • Lightweight and Comfortable to Wear
    Their construction makes triplets lighter, ideal for larger statement pieces or all-day wear.

  • Perfect for Fashion and Gift Jewellery
    Triplets are an excellent choice for first-time opal buyers, gifts, and trend-focused designs.

Ideal Uses for Doublets and Triplets

  • Earrings and pendants

  • Fashion rings

  • Statement jewellery

  • Gifts and everyday wear

  • Customers wanting genuine opal at an accessible price

These stones allow designers to create larger, brighter opal jewellery that remains comfortable, attractive, and affordable.

Transparency and Trust

Doublets and triplets are not solid opals, but they do contain real, natural opal. When clearly described and ethically sold, they are a legitimate and respected category within the opal industry.

Many jewellers choose doublets and triplets intentionally for:

  • Enhanced colour performance

  • Practical wearability

  • Design flexibility

  • Better value for customers