Australian Boulder Opal Specimen – Split Pair, Blue-Green Colour Play

This is a split-pair Australian boulder opal specimen — two halves of the same nodule, cut apart to reveal the colour bar running through the centre. Laid side by side, the pattern matches almost like a mirror: blue and purple fire pooling across a pale potch background, rimmed by dark, sandy ironstone. Splitting a boulder opal this way is a common step in preparing rough for cutting, and pairs like this are often kept together as a specimen precisely because the matching pattern shows how the colour actually sits inside the stone — something a single cut face can't always demonstrate.

About Boulder Opal

Boulder opal forms as veins of precious opal within ironstone matrix in the opal fields of Queensland — primarily Quilpie, Yowah and Winton. Unlike black opal from Lightning Ridge, the opal cannot be separated from its host rock; it's cut as a single solid piece, with the natural brown ironstone remaining as the stone's backing. This gives boulder opal its distinctive look — vivid colour against rich earth tones — and also makes it physically more durable than other opals, since the ironstone host is harder than the opal layer it carries.

Specifications

• Stone: Natural Australian Boulder Opal
• Size:  60 x 45 x 50 mm
• Colour Play:  Green-blue
• Matrix:  Ironstone
• Form:  Split-pair specimen (two matching halves)
• Origin:  Queensland, Australia
• Availability: One-of-a-kind — 1 piece (pair) available

Caring for a Display Specimen

Boulder opal is naturally more robust than solid opal because of its ironstone backing, but it's still a natural stone worth handling with a little care. Pick it up by the matrix rather than gripping the polished face, keep it somewhere stable where it won't be bumped off a shelf, and avoid sitting it in direct sun or right next to a heater — like any opal, sudden swings in temperature aren't ideal. A soft, dry cloth is all it needs to stay clean.

Provenance

Hand-selected by Joseph Bernecki, sourced direct from the Australian opal fields and set in his Sydney workshop. Meet him any weekend at The Rocks Market, stall under the bridge, Sydney. Read Joseph's story →

Common Questions