146.94ct Large Natural Koroit Boulder Opal front face view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal angled view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal back view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
146.94ct Large Natural Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image

Koroit Boulder Opal

This impressive 146.94ct Natural Boulder Opal from Koroit, Australia is a showpiece featuring dramatic, high-contrast matrix lines over a warm golden honey background. Vivid veins of opal fireranging from green to hints of orange and bluepeek through the swirls, giving it a mesmerizing visual depth. The large polished freeform surface and rounded contours highlight its naturally bold patterning, making it an ideal collectors stone or luxury statement piece.

Features & Benefits:
100% Natural Solid Boulder Opal Ethically sourced from Koroit, QLD, Australia
Striking Honey Matrix Rich swirls in earthy caramel and brown tones
Vibrant Opal Veins Glimpses of green, blue, and red fire throughout
Substantial Size 146.94ct, ideal for collectors or bespoke display jewelry
October Birthstone A meaningful and powerful gift option
One-of-a-Kind Artistry Koroit opals are celebrated for their intricate, nature-formed patterns

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.

Add to Wishlist

146.94ct Large Natural Koroit Boulder Opal

AU$693

In stock

Details

Dimension:

39x30x13 mm

Weight:

146.94ct

Type:

Natural Solid Untreated Boulder Opal

Source:

Koroit, QLD, Australia

Sku:

KK24

Koroit Boulder Opal

This impressive 146.94ct Natural Boulder Opal from Koroit, Australia is a showpiece featuring dramatic, high-contrast matrix lines over a warm golden honey background. Vivid veins of opal fireranging from green to hints of orange and bluepeek through the swirls, giving it a mesmerizing visual depth. The large polished freeform surface and rounded contours highlight its naturally bold patterning, making it an ideal collectors stone or luxury statement piece.

Features & Benefits:
100% Natural Solid Boulder Opal Ethically sourced from Koroit, QLD, Australia
Striking Honey Matrix Rich swirls in earthy caramel and brown tones
Vibrant Opal Veins Glimpses of green, blue, and red fire throughout
Substantial Size 146.94ct, ideal for collectors or bespoke display jewelry
October Birthstone A meaningful and powerful gift option
One-of-a-Kind Artistry Koroit opals are celebrated for their intricate, nature-formed patterns

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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