What is a Boulder Opal?
Boulder Opal is a beautiful type of precious opal that is unique to Queensland, Australia. Boulder Opal is usually found in Ironstone, but sometimes found in sandstone which is referred to as Boulder Opal or Crystal Boulder Opal. Boulder opal is popularly used in pendant necklace designs, as well as in rings by jewelers around the world. Boulder Opal often has an earthy, rock look and can host an array of colors; from blues and greens to rainbows and reds. Any color combination of boulder opal is possible. Boulder Opal can also host fossilised vegetation or wood which can be very interesting to collect or use in jewelry design. Furthermore; there are also Boulder Opal Nuts unique to the Yowah and Koroit mining fields. Every piece of boulder opal is unique; one and only.
Where is Koroit and Yowah?
Koroit and Yowah are two separate opal mining locations that both discover very unique types of opals. These mining locations are only a short distance from each other; within 100km. They are located in Queensland’s South West, about 1000km directly inland from the Gold Coast and Brisbane. There are other opal mining locations within the region as well including Quilpie and Eromanga.
Mining Boulder Opal in the Koroit / Yowah Region
Typical mines in the Koroit and Yowah region are open cut, with heavy machinery / bobcats and excavators often used to cut away at the harsh desert landscape. There are also mines that are drilled pits and worked by hand. When a promising area of colored boulder opal is discovered, manual labour by hand is often commenced with pick axes or jack hammers. Discovered opal is then sliced by machine, cut and polished into finished pieces like what we sell on our website.
What is so unique about Yowah and Koroit Boulder Opals?
There have been some stunning discoveries of beautiful vein-like opals. These types of boulder opals are very unique to Yowah. They are highly sought after pieces and often used in high end pendant necklace designs by jewellers. Yowah is also home of the famous Yowah Nut. Yowah Nuts are large boulder like rocks that are dug out of the ground. Most yowah nuts do not contain nice opals; but every now and then by luck and chance the miner will discover a beautiful, highly valuable Yowah Nut.
Koroit mining location in recent years has discovered a great deal of beautiful wood and vegetation opal fossils. A common type of opal from Koroit is often an easily distinguishable type of blue; easily recognisable in comparison to the colors from Winton. Koroit has also had some discoveries of nut-like opals as well. They are usually a little different compared to Yowah nuts however, with the vein like appearance being not as evident.
Example of a Yowah Vein Boulder Opal
Example of a Koroit Nut
What is Boulder Opal Worth, and what is it typically used for?
Boulder Opal is typically known as the most affordable of all the different types of opals. You can easily find affordable pieces of precious boulder opal under $100. Some of the rarer pieces with bright colors can be valuable however up to a few thousand dollars.
Larger pieces of boulder opal are commonly used in pendant necklace designs by jewellers. It is not uncommon to see boulder opal pendants hanging on ropes necklaces at markets around the world. Jewellers also enjoy using smaller pieces in ring stone designs that strive for an earthy look and feel. Collectors and investors also enjoy purchasing rare boulder opal specimens that are often too big to set in jewelry. We have a number of interesting, rare Boulder Opal specimens for sale in our collection.
A piece of Koroit Wood Fossil Boulder Opal that would look spectacular set in a pendant necklace