The World’s Biggest Opal 2025

The World’s Biggest Opal: A Giant Born of Fire and Time

When people think of opals, they often picture delicate gemstones — glowing with fire and colour, yet small enough to set into a ring. But hidden beneath the earth, nature occasionally creates giants. Among them stands a record-breaker: the world’s largest opal, a stone so immense it challenges how we imagine this gem of fire.

Meet “The Olympic Australis”

The Olympic Australis is the largest and most valuable gem opal ever discovered. Unearthed in 1956 at Coober Pedy, South Australia, this stone weighs an astounding 17,000 carats (3.45 kilograms / 7.6 pounds).

Unlike many rough opals, which are cut and polished into smaller stones, the Olympic Australis is so pure and spectacular that it has been left largely intact. Around 99% of the opal is of gem quality, with striking flashes of red, green, and blue dancing across its creamy white base.

The Discovery

The stone was found at a depth of about 30 feet in the “Eight Mile” opal field near Coober Pedy, during a period of booming opal mining in Australia. It was named in honour of the 1956 Melbourne Olympic Games, which were taking place that same year.

The opal’s size and beauty immediately made it a global sensation, earning the nickname “the Pride of Coober Pedy.”

Value Beyond Measure

When last valued, the Olympic Australis was estimated at over $2.5 million AUD — but experts suggest it could fetch far more today, given its rarity, provenance, and the rising demand for extraordinary natural gems. Unlike cut stones, its cultural and scientific value as the world’s largest gem opal makes it nearly priceless.

Why It Matters

The Olympic Australis is more than just a geological wonder — it is a symbol of Australia’s dominance in the opal world. Over 90% of the world’s gem-quality opals come from Australia, and this extraordinary stone highlights the continent’s unique geology and history.

For gem enthusiasts, it represents the very best of what opal can be: nature’s artistry at its most dramatic scale. For locals in Coober Pedy, it’s a source of pride, a reminder of the town’s role in shaping the world’s fascination with these fiery gems.

Other Notable Giants

While the Olympic Australis holds the crown, a few other enormous opals are worth mentioning:

• Andamooka Opal (South Australia): A 203-carat opal famously presented to Queen Elizabeth II in 1954.

• The Flame Queen: Known for its unique domed “eye” of brilliant red and gold, weighing 263.18 carats.

• Halley’s Comet Opal: Found in 1986 in Lightning Ridge, New South Wales, it weighs over 1,982 carats and is recognized as the world’s largest black opal.

Conclusion – A Giant of Colour and History

The Olympic Australis is more than a gemstone — it is a story carved in silica and time, an unmatched natural masterpiece that continues to captivate the world. Its size and quality may never be rivalled, making it one of the most iconic gems in history.

For opal lovers, it is the ultimate symbol of what makes this gemstone so extraordinary: the ability to capture the fire of the earth and the rainbow of the sky, all within a single stone.