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233ct Koroit boulder opal nut splits parcel of 5 pieces from Queensland, Australia showing concentric eye pattern with purple, blue, and teal opal veining. Natural, untreated.
233ct Koroit boulder opal nut splits parcel from Queensland, Australia showing matched pairs with purple and teal opal veining through amber ironstone. 100% natural and untreated.
233ct koroit boulder opal nut splits parcel 5pc RP233 - Group Shot

Boulder Opal Rubbed Rough

This 233 carat parcel contains 5 Koroit boulder opal nut splits sourced from the Koroit opal field in Queensland, Australia. The lot includes 2 matched split pairs and one single piece, all displaying the natural concentric eye formation that Koroit nuts are famous for.

Each piece has been split open to reveal the interior where opal has formed in concentric rings around a central ironstone core. Bright purple, blue, and teal opal veining outlines the oval shaped formations, creating a natural eye or target pattern that is instantly recognizable as Koroit material. The surrounding ironstone carries warm amber and reddish brown tones with natural texture and additional green opal veining running along the outer edges.

The two matched pairs are ideal for cutting into symmetrical cabochon sets for earrings, cufflinks, or twin pendant designs. Because each pair was split from the same original nut, the interior patterns mirror each other closely, giving cutters a natural matched set to work with. The single piece works well as a standalone pendant stone or display specimen.

All five pieces are large, with elongated oval shapes measuring approximately 40mm to 50mm in length. The size and natural formation make them equally appealing as polished cabochons or as natural display specimens in their current form.

All 5 opals are 100% natural and completely untreated. These are not doublets or triplets. Photographs were taken wet under LED lighting. Dry appearance will differ. Price includes worldwide registered shipping.

This collection will arrive securely packaged in an Opal Galaxy gift box, making it ready for safe storage, jewelry setting, or presentation as a collector gemstone.

Learn about Opal Cutting 

Shipping Updates - March 2026

Latest international delivery information from Australia Post and FedEx.

USA Tariff 

USA customers do not need to pay any tariffs on their purchase. Opal Galaxy covers all tariff charges to the USA, with no additional government fees added after checkout.

Delivery Status

USA: No delays
Asia: No delays
UK: Minor delays possible (Complimentary EMS Express upgrade)
Europe: Minor delays possible (Complimentary EMS Express upgrade)
Middle East: Shipping temporarily suspended - Please contact us to discuss shipping arrangements before purchase.

Shipping Information

All shipping includes complimentary insurance.

Registered Shipping $15 under $200
Free Registered Shipping over $201
Free Worldwide EMS Express Shipping over $1000
Free Worldwide FedEx Shipping over $4000
Extra Cost $25 EMS Shipping Upgrade under $200
Extra Cost $10 EMS Shipping Upgrade under $999
Extra Cost $100 FedEx Shipping Upgrade under $3999

Please view our Shipping Policy page for more information.

7 day return and refund policy.
Please view our Return and Refund page for more information.

We offer a lifetime guarantee for natural cracks that may form in our opals.
There is a very low chance that this can happen, however occasionally it might.
Our guarantee excludes any opals sold with existing fractures.
Please view our Terms and Conditions.

Caring for Your Australian Opal

Opal Jewelry

Important: Opals Are Fragile Gemstones
Opals are softer than sapphires, rubies, or diamonds and will crack or chip if struck hard against solid surfaces.

Always remove opal jewelry before:
Sports or physical activities
Manual labor, gardening, or gym workouts
Household tasks where impact is possible (lifting, moving furniture, etc.)

Even a minor knock during everyday wear can cause permanent damage. Treat opals as delicate gemstones, not everyday workwear.

Cleaning Your Opal

Clean with warm water and mild soap. Avoid harsh chemicals like bleach, ammonia, or chlorine. Light exposure to hand soap or dishwashing detergent is safe.

Storage

Store opal jewelry separately from harder gemstones (diamonds, sapphires) to prevent scratching.

Solid Natural Opals

(Black, Boulder, Crystal, White Opal)
Natural solid opals are stable and won't change color or crack from water, humidity, or temperature changes. They are safe to submerge in water and can be worn daily, provided they are protected from physical impact. Solid opals are a single piece of gemstone with no artificial backing, making them ideal for heirloom quality jewelry when handled with care.

Opal Doublets

Opal doublets consist of a thin slice of natural opal bonded to a dark backing. Do not submerge doublets in water as prolonged exposure can weaken the adhesive bond and cause separation or cloudiness. Remove doublet jewelry before swimming, bathing, or washing dishes. Clean with a damp cloth only; do not soak or use ultrasonic cleaners.

Like all opals, doublets are fragile and must be protected from impact.

Not sure which type you have? Solid opals show natural color throughout the stone. Doublets have a visible dark backing layer when viewed from the side.

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Boulder Opal Rubbed Rough Koroit Pairs Parcel 233ctw

AU$385

In stock

Details

Dimension:

See ruler in image

Weight:

233 ct total weight

Type:

Natural Solid Untreated Boulder Opal

Source:

Winton, QLD, Australia

Sku:

RP233

Notes

Quantity: 5 Pieces
2 X Split Pairs. Opals are wet to show color and taken under LED Lighting. Price includes Worldwide Registered Shipping.

Boulder Opal Rubbed Rough

This 233 carat parcel contains 5 Koroit boulder opal nut splits sourced from the Koroit opal field in Queensland, Australia. The lot includes 2 matched split pairs and one single piece, all displaying the natural concentric eye formation that Koroit nuts are famous for.

Each piece has been split open to reveal the interior where opal has formed in concentric rings around a central ironstone core. Bright purple, blue, and teal opal veining outlines the oval shaped formations, creating a natural eye or target pattern that is instantly recognizable as Koroit material. The surrounding ironstone carries warm amber and reddish brown tones with natural texture and additional green opal veining running along the outer edges.

The two matched pairs are ideal for cutting into symmetrical cabochon sets for earrings, cufflinks, or twin pendant designs. Because each pair was split from the same original nut, the interior patterns mirror each other closely, giving cutters a natural matched set to work with. The single piece works well as a standalone pendant stone or display specimen.

All five pieces are large, with elongated oval shapes measuring approximately 40mm to 50mm in length. The size and natural formation make them equally appealing as polished cabochons or as natural display specimens in their current form.

All 5 opals are 100% natural and completely untreated. These are not doublets or triplets. Photographs were taken wet under LED lighting. Dry appearance will differ. Price includes worldwide registered shipping.

This collection will arrive securely packaged in an Opal Galaxy gift box, making it ready for safe storage, jewelry setting, or presentation as a collector gemstone.

Learn about Opal Cutting 

Shipping Updates - March 2026

Latest international delivery information from Australia Post and FedEx.

USA Tariff 

USA customers do not need to pay any tariffs on their purchase. Opal Galaxy covers all tariff charges to the USA, with no additional government fees added after checkout.

Delivery Status

USA: No delays
Asia: No delays
UK: Minor delays possible (Complimentary EMS Express upgrade)
Europe: Minor delays possible (Complimentary EMS Express upgrade)
Middle East: Shipping temporarily suspended - Please contact us to discuss shipping arrangements before purchase.

Shipping Information

All shipping includes complimentary insurance.

Registered Shipping $15 under $200
Free Registered Shipping over $201
Free Worldwide EMS Express Shipping over $1000
Free Worldwide FedEx Shipping over $4000
Extra Cost $25 EMS Shipping Upgrade under $200
Extra Cost $10 EMS Shipping Upgrade under $999
Extra Cost $100 FedEx Shipping Upgrade under $3999

Please view our Shipping Policy page for more information.

7 day return and refund policy.
Please view our Return and Refund page for more information.

We offer a lifetime guarantee for natural cracks that may form in our opals. There is a very low chance that this can happen, however occasionally it might. Our guarantee excludes any opals sold with existing fractures.
Please view our Terms and Conditions.

Caring for Your Australian Opal

Opal Jewelry

Important: Opals Are Fragile Gemstones
Opals are softer than sapphires, rubies, or diamonds and will crack or chip if struck hard against solid surfaces.

Always remove opal jewelry before:
Sports or physical activities
Manual labor, gardening, or gym workouts
Household tasks where impact is possible (lifting, moving furniture, etc.)

Even a minor knock during everyday wear can cause permanent damage. Treat opals as delicate gemstones, not everyday workwear.

Cleaning Your Opal

Clean with warm water and mild soap. Avoid harsh chemicals like bleach, ammonia, or chlorine. Light exposure to hand soap or dishwashing detergent is safe.

Storage

Store opal jewelry separately from harder gemstones (diamonds, sapphires) to prevent scratching.

Solid Natural Opals

(Black, Boulder, Crystal, White Opal)
Natural solid opals are stable and won't change color or crack from water, humidity, or temperature changes. They are safe to submerge in water and can be worn daily, provided they are protected from physical impact. Solid opals are a single piece of gemstone with no artificial backing, making them ideal for heirloom quality jewelry when handled with care.

Opal Doublets

Opal doublets consist of a thin slice of natural opal bonded to a dark backing. Do not submerge doublets in water as prolonged exposure can weaken the adhesive bond and cause separation or cloudiness. Remove doublet jewelry before swimming, bathing, or washing dishes. Clean with a damp cloth only; do not soak or use ultrasonic cleaners.

Like all opals, doublets are fragile and must be protected from impact.

Not sure which type you have? Solid opals show natural color throughout the stone. Doublets have a visible dark backing layer when viewed from the side.

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