Boulder Opal Pendant – Sterling Silver, 35×16mm, Deep Blue, Semi-Dark

Thirty-five millimetres long. That's not a stone you tuck away — at 35×16mm this is the largest piece in the collection, a genuinely bold slab of Queensland ironstone carrying a sweep of blue opal colour across its face. Semi-dark body tone, medium brightness — the blue is deep and settled rather than electric, which is exactly right for a stone this size: it wears with authority rather than demanding your attention at volume. Boulder opal cut to this length follows the natural seam of the deposit, and the result is an elongated, sculptural shape that works beautifully as a statement pendant. Bezel-set in sterling silver on a 45cm rhodium-plated chain. If you've ever wanted to own a piece of Australian opal that genuinely makes a statement, this is it.

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.

Each boulder opal is shaped by the natural geometry of the seam, so freeform and irregular shapes are common. The dark ironstone backing acts as a natural backdrop that intensifies the colour play above it — similar to how the dark body tone of a black opal works, but achieved by geology rather than gemmology.

Specifications

• Stone: Solid Australian Boulder Opal (natural, untreated, ironstone matrix)
• Dimensions: 35×16mm
• Colour Play: Dominant blue
• Body Tone: Semi-dark
• Brightness: Medium
• Setting: Bezel, sterling silver
• Chain: Rhodium-plated, 45cm
• Origin: Queensland, Australia
• Availability: One-of-a-kind — 1 piece available

Caring for Your Opal

Opals are softer than diamonds or sapphires, so a little care keeps yours brilliant for generations. Boulder opal is more robust than other opal varieties thanks to its ironstone backing, but the precious opal layer still benefits from gentle treatment.

See Opal Care for storage, cleaning, and what to avoid.

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

This is a one-of-a-kind piece. Once sold, it cannot be replicated. Every opal at Rocks On The Rocks is hand-selected by Joseph for its individual character and quality.