Australian Boulder Opal

The Unique Character and Durability of Boulder Opal

Boulder opal is the second most valuable type of precious opal and is highly favored for its durability. The natural ironstone backing acts as a sturdy shield, giving boulder opal superior strength compared to other solid opals. Because the veins of precious opal in the boulders are very thin, lapidaries must cut the stone to follow the natural undulating lines of the color bar. This results in beautiful, organic, freeform shapes that make each gemstone entirely unique.

In this collection, buyers will find variety in styles, from Winton boulder opals displaying clean faces of rolling color to Koroit boulder opals showcasing intricate matrix veins running through the ironstone. Unlike composite doublets, boulder opal is a fully natural, one piece gemstone fused by nature over geological epochs. Shoppers can review details about shipping rates and options on the Opal Galaxy shipping policy page. Geological studies published by Geoscience Australia describe these formations within the Cretaceous Winton Formation of southwest Queensland.