39.17ct Double Sided Koroit Boulder Opal front face view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal angled view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal back view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image
39.17ct Double Sided Koroit Boulder Opal detail view Australian opal gemstone Opal Galaxy product image

Koroit Boulder Opal

This 39.17ct Natural Koroit Boulder Opal from Koroit, Queensland showcases a stunning double-sided matrix pattern across its oval surface. The intricate network of honey-gold and deep brown ironstone is beautifully interspersed with bright flashes of blue, green, and violet. Both sides are highly polished, offering visual interest from every angle. A captivating piece perfect for collectors or as a statement in high-end custom jewelry.

Features & Benefits:
100% Natural Solid Boulder Opal Mined from Koroit, QLD, Australia
Double-Sided Beauty Unique matrix pattern with vivid play-of-color on both faces
Earthy Brown Ironstone with Color Fire A mesmerizing mix of natures tones
High Polish Finish Ready for display or setting in fine jewelry
October Birthstone A meaningful and personal gift
Large and Weighty Ideal as a center stone or collectors showpiece

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 $80 FedEx Shipping Upgrade under $3999

All shipping includes complimentary insurance.
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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39.17ct Double Sided Koroit Boulder Opal

AU$385

In stock

Details

Dimension:

32x23x7 mm

Weight:

39.17ct

Type:

Natural Solid Untreated Boulder Opal

Source:

Koroit, QLD, Australia

Sku:

KK29

Koroit Boulder Opal

This 39.17ct Natural Koroit Boulder Opal from Koroit, Queensland showcases a stunning double-sided matrix pattern across its oval surface. The intricate network of honey-gold and deep brown ironstone is beautifully interspersed with bright flashes of blue, green, and violet. Both sides are highly polished, offering visual interest from every angle. A captivating piece perfect for collectors or as a statement in high-end custom jewelry.

Features & Benefits:
100% Natural Solid Boulder Opal Mined from Koroit, QLD, Australia
Double-Sided Beauty Unique matrix pattern with vivid play-of-color on both faces
Earthy Brown Ironstone with Color Fire A mesmerizing mix of natures tones
High Polish Finish Ready for display or setting in fine jewelry
October Birthstone A meaningful and personal gift
Large and Weighty Ideal as a center stone or collectors showpiece

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 $80 FedEx Shipping Upgrade under $3999

All shipping includes complimentary insurance.
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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