Boulder Opals are a relatively rare type of Opal that is only found in the arid Queensland territory of central Australia.
How are Boulder Opals formed?
This stunning gemstone is formed over millions of years when silica-rich water finds its way through cracks, crevices and cavities in the rock surrounding it and then slowly evaporating, leaving the gorgeous opal behind. Silica from dissolved sand trickled down and throughout ironstone boulders and the silica precipitated out of solution. Generally, the opal is found within boulders which need to be broken open. These are found in clay layers just above the ironstone.
1: OOAK, Okaaay?
Since boulder opals form in nooks and crannies, the patterns that form from the combination of these two minerals makes each stone truly one of a kind. There are no two boulder opals that look the same! When round brilliant white diamonds can be ubiquitous and just sort of ‘blah’, the same-old blue sapphires leave you unimpressed, each boulder opal that you’ve seen is a true individual with its own color palette, patterning and overall shape.
2: Hard As A Rock….
Due to the hardness of Ironstone, boulder opal is considered a lot more tough compared to other kinds of jewelry-grade opals. Opal is merely a 5 out of 10 on the Mohs scale of hardness, making it a relatively soft gemstone. Due to this, opal is quite easy to scuff, scratch and ultimately, break from everyday bumps and normal wear. The matrix of brown ironstone is much harder and more durable, which acts as a strong foundation for and aesthetic contrast to the shimmering bright colors of the opal. This resilience makes boulder opals fantastic for all articles of jewelry — including bracelets and rings. Most jewelers, including us, tend to recommends setting sensitive or fragile gemstones in necklaces or earrings to avoid accidental scratches, chips or total breakage.
3: Responsible Sourcing: Yes Please!
Another favorable quality of Boulder Opal is that it is considered to be one of the most ethically-sourced gemstones available on the market. Safe working conditions for the miners in Queensland can be attributed to an overall high standard of safety and environmental consideration by the Australian government.
The miners do everything themselves, from moving earth, breaking boulders, mining the opal, to sorting, cutting, and polishing. Some miners choose to cut their opals on-site in a camper van or RV using solar power!
At the end of the life of the mine or when the lease has to be returned, all the original dirt and top layers of rocks that were there previously must be put back as it was. The land is refilled and the temporary dwellings are fully removed. Vegetation grows naturally in this climate and it is difficult to tell that a mine once occupied the site. This effective method of post mining clean up makes for a beautiful gemstone with the important quality of being more environmentally-conscious than many other stones out there.
Concluding Thoughts
These three favorable qualities make for a gemstone that we believe is under-appreciated by the jewelry industry and jewelry wearers alike! This may seem like an oversight by the masses on its face, but we think it’s deeper than that. One reason could be due to its aesthetic boldness. The brown ironstone combined with every color in the rainbow can be an intense look, and not everyone is open-minded enough to embrace it (kidding). Its relative rareness could also be a contributing factor. Rare and uncommon gemstones tend to be less popular overall when compared to heavy hitters like emeralds, sapphire, ruby or diamonds. Sometimes being too difficult to find makes something lesser known by the world at large.
Thanks so much for reading and spending some time enjoying our ruminations about this fantastic gemstone!