Yowah Nut Opal

what are yowah nut opals?

are really small boulder opals that look roughly like a nut from a tree.  They can be as small as an apricot seed or as large as a Mango seed.  When the nut opens up they often have layers of brown, roundish patterns much like a lemon peel that eventually, as you get to the center of the stone, ends up in either an empty cavity or an area filled with opal.

Just how the ‘kernel’ of the nut got filled with precious opal was a complete mystery until geologists and others worked out that a long time in the past the boulder ironstone ‘nuts’ were not as hard as they are today.  In fact at one stage of the development they were quite porous, allowing a mater based chemical mix, seep down into them.

In time, this chemical ‘soup’ containing silica, dried out and left a residue which ended up being either common or precious opal.

The first time I saw a Yowah Nut opal was back in 1968

My wife and I were doing a tour of the outback. We were in Charleville, western Queensland at the time.  Someone said ‘would you like to visit the “opal” mining “nut” town of “Yowah”  The temptation was too great and we have always been happy we made that decision.  It really changed our lives in more ways than one.

In those years, as probably is still the case today with, a few mines were set aside for tourists to try their luck. We located the tourist mines, and for our convenience, there was a ladder you could go down. Some of our friends were not willing to take the risk, and probably today you would not be permitted to do so, but Renate and I and a couple of others couldn’t resist the temptation, and we lowered ourselves down into the depths of the earth to get the opals.

Conveniently, someone had left some pics and shovels down there as well, so we enjoyed digging away hoping to find the nuts.  Suddenly something glimmered from the wall of the ‘cave’ and we gauged out a really nice chunk of what we later found out was a matrix boulder opal, meaning that the color was more scattered throughout the ironstone rather than in one clump like a Yowah nut.

At that early stage or our opal experience, we believed that for an opal to be valuable, it had to be all opal and no mixture of other impurities or remnants of its ironstone ‘mother.’  We didn’t realize at the time that Yowah nut opals hold a fascination that extends far beyond just looking at opal itself.  In fact a feature of this type of gemstone is the amazing patterns and shapes that present themselves as a result of all sorts of external influences from volcanic action, the rushing of water from giant floods, and other seismic activity.  These  patterns are so unique and rare that, at times even if precious opal itself is not a feature of the stone, the graphic presentation almost makes the appearance of opal irrelevant.

Yowah nut opals Examples

Here are examples of a “Yowah nut opals” and other boulder pictures stones.


Interestingly this demand often surfaces among manufacturing jewelers.  Particularly those who specialize in hand made creations rather than mass produced standard sized castings.  Designers see the immediate potential in “Yowah nut opals“.  Not just because of their rarity and interest factor, but because of their endless design potential.  Most of these “Yowah nut opals” are usually cut in free form shape, naturally cleaved out of the rock by the lapidarist.  This means that designers of Yowah Nut jewelry do not have to stick to traditional, often boring rounds, ovals and naivete (pointed end) shapes.  They can use their imagination to create designs that are totally different; affording the final owner of the piece to have something that they can truly say is unique.