40 Results: New & Used in boulder opal in Australia

A loose gemstone purchased from an Adelaide jeweller and gemstone dealer in 2010. It has been polished and is ready to be set into a ring or pendant. Unique item, best viewed up close. Australian Boulder opals are the second most valuable type of opal. They are distinguished by their layer of solid brown ironstone left on the back of the stone. As the name suggests, boulder opals are mined from large ironstone boulders under the ground.

Shining streak of precious green opal showing on main face of rock. A second similar green opal formation showing on adjacent surface. Attractive wood grain-like patterns in the host rock. Traces of potential additional seams to explore. Perfect for cutting to jewellery stones or keep as specimen. High density ironstone host rock mined at Winton opal fields. Weight approximately 67 grams Dimensions approximately 5 x 4 x 3 cm Some photos in outdoor daylight, dry as-mined condition. Some photos w

Red line of precious colour shining out along the main face opal. Paint-like formation of opal steeaks along main face of rock. Opal formation runs along adjacent surface and opposite face. Distinctive white opal line alongside colour opal adds character. Traces of potential additional seams to explore. Great for for cutting to multiple artisan picture stones. Ironstone host rock mined at famous Winton opal fields. Weight approximately 488 grams Dimensions approximately 9 x 7 x 4 cm Some photos

Queensland teardrop boulder opal. A beautiful opal, weighing 7.5 cts and measuring 23mm x 11mm x 3mm, showing mainly blues, greens, and some purple. It's ready for you to have set in a pendant or ring. Please contact me with any questions or to make an offer.

Alstonville nsw Australia boulder opal polished 3.55 ct with all colours.

Stunning boulder opal many colours in this unique gem.

Beautiful piece of qld boulder opal.9ctw

Like an art painting from nature on this natural ancient rock. Swirling deposits of opal showing on front surface of the rock. Purple and blue precious opal with a distinctive white opal line. Traces of potential internal seams to chase and explore. Suits cutting to picture stones or keep as a desk-top talking-point. Ironstone host rock mined at famous Winton opal fields. Weight approximately 1842 grams Dimensions approximately 15 x 14 x 8cm Some photos in outdoor daylight, dry as-mined conditi

Rich red blocks of brilliant opal dominant the play of colour. A vivid display of full-face rainbow colours flash across the stones. Shining bright blues and greens add complexity to the palette. Top quality doublet opals with natural boulder ironstone backing. Expertly cut and assembled to a well-matched teardrop pair. Mine Area: Lightning Ridge, New South Wales, Australia. Body Tone: N3 Doublet Black Opal. Brightness: B5 Vivid. Classification: Composite Natural Opal Approx, total weight 0,35

A brilliant display of red dominant colours flash across the stones. Green sparkles highlight the overall play of opal colour. Top quality doublet opals with natural boulder ironstone backing. Expertly cut and assembled to nicely matched round set of three. Mine Area: Lightning Ridge, New South Wales, Australia. Body Tone: N4 Doublet Black Opal. Brightness: B4 Very Bright. Classification: Composite Natural Opal Approx. total weight 1.10 Carats. Approx. sizes (1): 5.07x5.05 x 2.09mm (2) 5.08 x 5

**** VERY RARE Boulder Opal - loose gem ***** *****Amazing Display of colours ***** Variety: Natural BlackBoulder Opal Type 2 Body Tone: Black N1 (1) Brightness: Vivid Transparency: Opaque Colour: Multicolour Hue: Deep Rich Tones Outline: Free Shape Profile: Medium Cabochon Origin: Queensland Pattern: Mixed Pattern Display: Good from All Angles Distribution: Over 80% Inclusions: No Inclusions MOHS Scale: 4.5-6.5 Polish: 2.15 0.08-0.09 R.F.I.: 1.450 0.020 Spec Gravity: 1.98 -

Sky blue deposits of precious opal across main rock front face. Purple opal and lilac crystal showing reverse face of main rock. Traces of additional potential opal seams to explore. Cut to finished stones or polish and keep as a specimen. Bonus mine-run rock included for cutting and grinding practice. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Main Rock: weight approx. 280 grams Main Rock: dimensions approx. 8 x 6 x 4 cm Bonus Rock: weight

Slate blue formation of opal showing on main rock front face. Swirls of opal formations on adjacent face of main rock. Precious green opal seam running on reverse face of main rock. Visibility of additional potential opal seams to explore. Cut to finished stones or polish and keep as a specimen. Bonus mine-run rock included for cutting and grinding practice. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Main Rock: weight approx. 102 grams Main

Purple deposit of opal showing on main face of rock. Lilac opal formations of reverse face of the rock. Clear visibility of purple opal seam to open and explore. Ideal starter rock for lapidary cutting and polishing practice. Cut to finished stones or polish and keep as a specimen. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Weight approximately 281 grams Dimensions approximately 9 x 5 x 4 cm Some photos in outdoor daylight, as-mined dry con

Formation of slate green opal on main face of rock. Multiple matrix-like opal nuggets sparkling on reverse face. Clear visibility of numerous opal seams to chase and explore. Great starter rock for lapidary cutting and polishing practice. Cut to finished stones or polish and keep as a specimen. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Weight approximately 227 grams Dimensions approximately 8 x 5 x 4 cm Some photos in outdoor daylight, as-

Formation of opal showing on main face of rock. Precious purple colour grading to lavender and lilac. Paint-like smears of opal of adjacent surface of rock. Traces of potential opal seam to chase and explore. Good starter rock for lapidary cutting and polishing practice. Cut to finished stones or polish and keep as a specimen. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Weight approximately 106 grams Dimensions approximately 7 x 4 x 3 cm Som

Paint-like formation of opal showing on main rock face. Sparkling green precious opal display on one section. Distinctive white opal deposit lines add character. Traces of additional potential opal seams to explore. Cut to picture stones or polish and keep as a specimen. Bonus mine-run rock included for cutting and grinding practice. Ironstone host rock from famous Winton opal fields. Mine Area: Central West Queensland, Australia Main Rock: weight approx. 116 grams Main Rock: dimensions approx.

Incredible patterns of opal and rock formations like an oil painting. Rich deposits of purple, blue, caramel, and cream opal on multiple faces. Two tone wood-like rock patterns of ironstone and sandstone. Clear visibility of additional opal seams and nuggets to open and explore. Ideal for cutting to many artisan jewellery stones or keep as specimen. High density ironstone host rock mined at famous Winton opal fields. Weight approximately 452 grams Dimensions approximately 10 x 9 x 5 cm Some pho

Paint-like purple and green opal formations on main face of rock. A nugget of precious green opal showing on underside surface. Traces of potential additional opal seams to chase and explore. Perfect as a starter rock for lapidary work to cut finished stones. Size and shape suits well to keep as-is for a desk-top specimen. High density ironstone host rock mined at Winton opal fields. Weight approximately 409 grams Dimensions approximately 12 x 7 x 4 cm Some photos in outdoor daylight, dry as-mi

Brilliant green precious opal deposits shining on two faces of rock. Paint-like opal formations showing on adjacent two faces of rock. Traces of potential additional opal seams to chase and explore. Great for cutting to multiple picture stones or keep as specimen. High density ironstone host rock mined at famous Winton opal fields. Weight approximately 358 grams Dimensions approximately 7 x 6 x 5 cm Some photos in outdoor daylight, dry as-mined condition. Some photos wet to simulate polishing p

Formations of purple opal showing across main face of rock. Deposits of purple, blue and lilac opal on adjacent two faces. Large formation of lilac-hue jelly crystal opal on top surface. Traces of potential additional opal seams to chase and explore. Ideal for cutting to multiple jewellery finished stones. Ironstone host rock mined at Winton opal fields. Weight approximately 280 grams Dimensions approximately 7 x 6 x 4 cm Some photos in outdoor daylight, dry as-mined condition. Some photos wet

Wonderful colour palette of precious opal on main two faces. Lagoon greens and blues transition to purples and violets. Additional paint-like opal deposit on third face of rock. Traces of potential additional opal seams to explore. Ideal for cutting to multiple beautiful jewellery stones. High density ironstone host rock mined at famous Winton opal fields. Weight approximately 138 grams Dimensions approximately 6 x 4 x 4 cm Some photos in outdoor daylight, dry as-mined condition. Some photos we

Bright formation of violet coloured precious opal on main face of rock. Adjacent white opal formation line adds definition and character. A paint-like deposit of opal on side face of the rock. Traces of potential additional opal seams to explore. Ideal for cutting lapidary starter-level stones. High density ironstone host rock mined at Winton opal fields. Weight approximately 90 grams Dimensions approximately 7 x 4 x 2 cm Some photos in outdoor daylight, dry as-mined condition. Some photos wet

Brilliant and rare boulder opal Kernel/nut polished.