• Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash
  • Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash
  • Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash
  • Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash
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Rocks On The Rocks

Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash

Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue & Green Flash

$850.00 AUD
$850.00 AUD
Sale Sold out
Taxes included. Shipping calculated at checkout.

This is a loose, unset solid boulder opal from Quilpie in South West Queensland — ready for a collector's cabinet or to be taken straight to a jeweller for a custom setting. It weighs 10.54 carats and measures 18×15mm, cut to a free-form shape that follows the natural contours of the stone. The body is semi-dark, deep enough to give the colour real contrast without reading heavy. Across that background, blue dominates — a clean, saturated flash that shifts as the stone moves — with a secondary flash of green that rolls in from different angles. The ironstone matrix is intact on the back, just as nature left it. One stone, no treatments, no enhancements.

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: Solid Boulder Opal
  • Carat Weight: 10.54ct
  • Dimensions: 18×15mm
  • Colour Play: Blue with green flash
  • Body Tone: Semi-dark
  • Brightness: Medium
  • Shape: Free-form / natural
  • Origin: Quilpie, Queensland
  • Availability: One-of-a-kind — 1 stone available

Caring for Your Opal

Opal is softer than diamond or sapphire, so a little care goes a long way. 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

Can this stone be set into jewellery?
Yes — that's exactly what it's built for. Joseph can set it into a pendant, ring, or brooch in his Sydney workshop; just get in touch and he'll talk you through options and quote a price. Alternatively, take it to your own jeweller — boulder opal works well in bezel and partial bezel settings that protect the edge while keeping the face open to the light.
Why does boulder opal have brown on the back?
The brown material is the natural ironstone host rock — it's not a backing that's been added. Boulder opal forms inside ironstone boulders in Queensland, and the opal layer can't be separated from it without destroying the stone. The ironstone stays on as part of the piece, which is why boulder opal is considered a solid natural stone even though it looks layered. It also makes the stone tougher than a thin polished opal slice would be on its own.
Certification, shipping, returns?
Every piece is backed by Joseph's personal guarantee, ships fully insured within Australia, and can be returned within 14 days. See Buying an Opal for the full breakdown.
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