Yowah Opal Nut

Hidden deep in the heart of Outback Queensland, the tiny town of Yowah is home to one of the world’s most unique and beautiful gemstones – the Yowah Opal Nut.

Formed over millions of years, Yowah Opal Nuts are ironstone concretions – round or oval-shaped rocks that often contain stunning opal inside. From the outside, they may look like ordinary brown stones, but crack them open and you might reveal a dazzling play of colour, from deep blues and fiery reds to brilliant greens and purples.

What makes the Yowah Opal Nut so special is its natural, self-contained form. Unlike most opals that are found in seams or veins, these nuts are compact, whole, and often display opal patterns across their surface or hidden inside their centre – like nature’s own treasure chest.

Yowah is one of the only places in the world where these opal nuts are found, and fossicking for them is a favourite activity for visitors. Whether you’re a seasoned opal hunter or just curious to try your luck, the thrill of cracking open a nut and discovering a flash of colour is something you’ll never forget.

Yowah Opal Nuts begin their journey in the ancient sediments of the Great Artesian Basin, one of the world’s largest underground water systems. Around 100 million years ago, this region was covered by an inland sea. As the sea receded, layers of sand, clay, and ironstone were deposited and compacted over time.

In certain conditions, small ironstone concretions (rounded lumps of iron-rich rock) formed within these layers. These would later become what we now call “nuts” because of their size and shape—often resembling walnuts or small eggs.

But the magic happens inside.

Water rich in silica—a compound released from decaying organic matter and weathered rocks—slowly seeped through the ground. In the right conditions, this silica-laden water found its way into tiny cavities, cracks, and voids inside the ironstone nuts. Over millions of years, as the water evaporated, it left behind deposits of precious opal.

This process is incredibly rare and specific to Yowah and nearby opal fields like Koroit. That’s why Yowah Opal Nuts are so treasured – they are a unique product of place, time, and geology.

First things first!

Jump online a grab a fossicking license. They are easy to get and not expensive.

Then pack your swag and head to Yowah, just under a 2 hour drive from Cunnamulla. Or call the Artesian Waters Caravan Park and book in one of their motel rooms.

You will find the caravan park sells fossicking gear or the Rural Transaction Centre (RTC) hires it out.

The fossicking area is just about 800m from the town centre so a 2 minute drive or 15 minute walk.

Then start looking around. The Yowah Opal Nuts are ironstone concretions. They often show as roundish, brown lumps on or just below the surface. You can try and crack open any you find, or throw them in your bucket and head back to town.

There are plenty of “backyard” opal shops throughout the town and plenty of people to help and give advice. And who knows, you may have just found your fortune with a priceless Yowah Opal Nut.

Yowah Nut Opals are highly prized by collectors and jewelers for their unique patterns and the natural artistry revealed upon cutting or polishing.

The “Yowah Moon” opal is an extraordinary specimen of Yowah Nut opal, valued at $200,000, unearthed in 2020 by Indigenous Australian opal miner David Darby at Brandy Gully near Yowah, Queensland. This opal, notable for its avocado-like shape and weighing nearly 400 grams, showcases vibrant flashes of blue and green within its ironstone shell. Recognizing its exceptional rarity and cultural significance, Geoscience Australia acquired the Yowah Moon in 2024 with support from the National Cultural Heritage Account, ensuring its preservation within Australia’s national collection. The opal is now featured in Geoscience Australia’s “Rocks That Shape Australia” exhibition in Canberra, serving as a testament to the country’s rich geological heritage and the enduring legacy of opal mining in the Yowah region