Frequently Asked Questions
How Much is an Unset Opal Worth?
The value of Loose Opals is difficult to assess, as each characteristic of an opal plays a role in determining its worth. According to the opal's gemstone type, body tone, clarity, pattern, colour bar thickness, colour play, and flaws all play a role in determining its worth. In addition, the quality of the cut, polish, and the size of the gemstone are all crucial factors to consider.
Loose Opals are meticulously examined and assigned a price per carat when it is evaluated. The opal's price is determined by the total carat size of the stone.
Generally, Loose Opal gemstones with a black or dark body tone showcase a more vibrant play-of-colour, which is considered more valuable than opals with a white, light, or crystal body tone. As a result, loose Black Opals may cost over $10,000 AUD per carat as the most valuable form of opal.
The clarity of an opal’s colour is critical when assessing the value of Unset Opal. Red fire is the rarest colour, followed by green/orange, green/blue and blue. Therefore, a Red Fire Opal is generally more valuable than a predominantly green opal, which is more valuable than a stone showing only blue colour.
However, the brilliance and clarity of an opal’s proportioned pattern is the main decision-maker. A brilliant blue/green can be more valuable than a dull red; bright twinkling stars of a ‘pin fire’ pattern can be more valuable than a cloudy ‘open’ or ‘mixed’ pattern of similar colouration; or a brilliant, lustrous light opal can sell more than a lack-lustre Black Opal.
What is the Best Type of Unset Opal?
Black Opals and Boulder Opals are arguably the rarest of all opal gems and are absolutely magnificent gemstones.
The Boulder Opal is a diminishing resource – which means it is genuinely running out. So if you are looking for an incredibly unique and genuinely rare form of opal, then Boulder Opal is the one! Hand-cut in Sydney NSW, Loose Black Opals with gem colour and a "named" pattern are 5000x rarer than diamond.
Loose Black Opals are so rare because Black Opals can only be found in one place on earth, a small 30km square field in north-western NSW called Lightning Ridge. However, intense Black Opals that really mesmerises can be worth many tens of thousands. Black Opals are in a class of their own for beauty, with their rainbow variety of hues blossoming in fire-like patterns, from oranges, greens, blues and flashes of red, pink and indigo.
However, customers should be aware that many online stores stock a form of fake Black Opal, which are dyed and treated Ethiopian Opal. Whilst still being an authentic type of opal, they are visibly unrecognisable from a Black Opal, but structurally they are extremely prone to cracking and losing colour because the dying treatment can be affected or reversed by household chemicals.
Precious Unset Opal
There are two basic types of opal, precious opal and common opal. Precious opal displays a spectrum of colours, whereas common opal does not. The most precious opal to date has been mined in Australia as this is where the colours and patterns found are the most intense.
Some common types of Loose Precious Opals we sell at Opal Cutters:
Pinfire Opal – also known as "Pinpoint" Opal – is opal with pinpoints of colour throughout the stone.
Boulder Opal – is formed in cavities and cracks of ironstone, usually from Queensland, Australia
Black Opal or Dark Opal – are naturally occurring, rare and valuable solid opal formed in Iron oxide found in Lightning Ridge in Northern NSW. This opal has a dark body-tone colour, often black or dark grey.
Harlequin Opal – has patches of colour in the shape of rectangles or diamonds.
Cat's-Eye Opal – a rare, phenomenal opal from Madagascar, which displays chatoyancy, the optical effect that produces a thin line of bright light across the surface of a stone. The line, or the "cat’s eye", tracks back and forth across the dome of the stone as the stone and light source moves.
Common Unset Opal
There are two basic types of opal, precious opal and common opal. Common opal does not exhibit play-of-colour, instead, it is usually opaque to translucent and brownish-orange in colour. Common opals got their name because they are found in many locations throughout the world. Most common opal specimens are also "common" in appearance and do not attract much commercial attention compared to precious opals.
Despite the underwhelming name, common opals are still attractive and have beautiful colour, perfect for jewelry. Some popular types of Loose Common Opals we sell at Opal Cutters:
Pink Opal – also occurs in shades of pink, common opal mined in Peru. The range in colour is from nearly white, through carnation pink, through lilac.
Morado Opal – has a purple body colour produced in Mexico.
Blue Opal – is a Solid Black Opal with the common blue covering the entire stone. Sometimes called "blue opal" and "blue on black".
Black Crystal Opal – is a Solid Black Opal, which is transparent due to little or no iron oxide on the back. Viewed from the top, it compares at least with N3 in darkness rating.
Crystal Opal – is a transparent/translucent opal. Sometimes mistaken for "light opal" found in Coober Pedy in South Australia.