Gem Profile- Boulder Opal
This article is one of a six-part series on Opal. Here is a complete list of our Opal articles: An Opal Introduction, Common Opal, Black Precious Opal, White Precious Opal, Opalized Fossils, Boulder Opal
Throughout this short series on opals, we've covered a lot of basic information about this fascinating stone.
Most common opal lacks a play of color, but because it is abundant, soft, and comes in many colors with an internal glow, it makes beautiful carvings.
Some "common" opals aren't so common, such as Mexican jelly opal and the blue and pink opals from South America, which work beautifully as cabochons.
Rare, precious black and chocolate opals are found in specialized locations and display stunning play-of-color, while milky white opals remain the most well-known.
Opalized fossils are the remains of prehistoric life coated or filled with opal, making them especially unique.
Crystal or clear opal can be faceted, but the most popular opal for wire jewelry artists is boulder opal.
WS Faculty member Lindi Schneck had the wonderful opportunity to visit Australia. Of course, while there she purchased boulder opal cabochons and used one to create this lovely wire pendant.
Most common opal lacks a play of color, but because it is abundant, soft, and comes in many colors with an internal glow, it makes beautiful carvings.
Some "common" opals aren't so common, such as Mexican jelly opal and the blue and pink opals from South America, which work beautifully as cabochons.
Rare, precious black and chocolate opals are found in specialized locations and display stunning play-of-color, while milky white opals remain the most well-known.
Opalized fossils are the remains of prehistoric life coated or filled with opal, making them especially unique.
Crystal or clear opal can be faceted, but the most popular opal for wire jewelry artists is boulder opal.
WS Faculty member Lindi Schneck had the wonderful opportunity to visit Australia. Of course, while there she purchased boulder opal cabochons and used one to create this lovely wire pendant.
Boulder Opal
Boulder opal, which resembles precious black opal, is found only in Australia.
In Queensland, thin opal formed on a matrix of iron-rich sandstone called ironstone. To extract it, heavy excavation produces large chunks of ironstone, known as boulders.
Traditionally, a boulder is a rounded, independent mass of rock, but the term now also applies to rough-edged stones detached from their original location.
Boulder opal displays an amazing array of colors and has low water content, making it very stable and unlikely to craze or crack over time.
When the opal forms veins throughout the ironstone, it is specifically called matrix opal.
Rough boulder opal sent to Dale from a fellow wire artist who lives in Australia and is allowed by their government to "noodle," or search tailings piles at certain mines.
Boulder opal, which resembles precious black opal, is found only in Australia.
In Queensland, thin opal formed on a matrix of iron-rich sandstone called ironstone. To extract it, heavy excavation produces large chunks of ironstone, known as boulders.
Traditionally, a boulder is a rounded, independent mass of rock, but the term now also applies to rough-edged stones detached from their original location.
Boulder opal displays an amazing array of colors and has low water content, making it very stable and unlikely to craze or crack over time.
When the opal forms veins throughout the ironstone, it is specifically called matrix opal.
Rough boulder opal sent to Dale from a fellow wire artist who lives in Australia and is allowed by their government to "noodle," or search tailings piles at certain mines.
Boulder opal is challenging to cut into domed cabochons because of the way opal seams and veins form within the ironstone matrix.
As a result, most boulder opals are shaped into freeform, flat pieces.
Lapidaries usually cut the stone to keep most of the opal on one side of the matrix. If the opal splits down the middle a "boulder opal split" each side can be mirrored and made into matching earring cabochons.
Boulder opal is classified by the color of its matrix: black, crystal, or light.
Its play of color can include red, orange, green, blue, purple, and even pink.
Beverly Brown created this boulder opal pendant by wrapping the stone in 24-gauge gold filled wire.
As a result, most boulder opals are shaped into freeform, flat pieces.
Lapidaries usually cut the stone to keep most of the opal on one side of the matrix. If the opal splits down the middle a "boulder opal split" each side can be mirrored and made into matching earring cabochons.
Boulder opal is classified by the color of its matrix: black, crystal, or light.
Its play of color can include red, orange, green, blue, purple, and even pink.
Beverly Brown created this boulder opal pendant by wrapping the stone in 24-gauge gold filled wire.
Although boulder opal may seem new to the gemstone market, it was first discovered in the 1870s.
When precious black opal was found in New South Wales in 1903, boulder opal was largely forgotten until the 1980s.
Shopping for boulder opal can be confusing because ironstone is often used as backing for doublets and triplets of precious black or white opal.
True boulder opal should be sold by the piece, not by carat or gram weight.
Freeform boulder opal cabochons, cut by Charlie Armstrong.
When precious black opal was found in New South Wales in 1903, boulder opal was largely forgotten until the 1980s.
Shopping for boulder opal can be confusing because ironstone is often used as backing for doublets and triplets of precious black or white opal.
True boulder opal should be sold by the piece, not by carat or gram weight.
Freeform boulder opal cabochons, cut by Charlie Armstrong.
Yowah Nut and Koroit Opals
A specialized type of boulder opal is called Yowah Nut, found only in the Yowah opal fields of Australia.
Here, pockets of crystal-clear opal with electric colors formed within hard conglomerations of clay and ironstone.
When the matrix rock is cut away to reveal the opal pocket, the result resembles a nut.
For an excellent example of a Yowah Nut, visit the Smithsonian's Department of Mineral Sciences page.
The opal cabochon in the back is a Koroit opal and the one in front with deep purple veins is from a Yowah Nut.
Private collection, Dale Armstrong.
A specialized type of boulder opal is called Yowah Nut, found only in the Yowah opal fields of Australia.
Here, pockets of crystal-clear opal with electric colors formed within hard conglomerations of clay and ironstone.
When the matrix rock is cut away to reveal the opal pocket, the result resembles a nut.
For an excellent example of a Yowah Nut, visit the Smithsonian's Department of Mineral Sciences page.
The opal cabochon in the back is a Koroit opal and the one in front with deep purple veins is from a Yowah Nut.
Private collection, Dale Armstrong.
One of the other well known boulder opal fields in Queensland, Australia is Koroit.
I found this blog by Gene McDevitt, Koroit Opal News, to be an extremely interesting way to learn more about how this boulder opal is mined and then cut.
He also includes excellent photos of the wildlife that share their habitat with opal miners.
A boulder opal cabochon made into a wired necklace component by WS Faculty member Lindi Schneck.
I found this blog by Gene McDevitt, Koroit Opal News, to be an extremely interesting way to learn more about how this boulder opal is mined and then cut.
He also includes excellent photos of the wildlife that share their habitat with opal miners.
A boulder opal cabochon made into a wired necklace component by WS Faculty member Lindi Schneck.
Resources
Print Resources:
Gemstones of the World by Walter Schumann, ISBN 0-8069-3088-8
Minerals of the World by Walter Schumann, ISBN 0-8069-8570-4
Opals by Fred Ward, ISBN 1887651047
The World of Opals by Allan W. Eckert, ISBN 0471133973
Internet Resources:
Boulder, beedictionary.com
Koroit Opal News : koroit.blogspot.com
Smithsonian National Museum of Natural History
Print Resources:
Gemstones of the World by Walter Schumann, ISBN 0-8069-3088-8
Minerals of the World by Walter Schumann, ISBN 0-8069-8570-4
Opals by Fred Ward, ISBN 1887651047
The World of Opals by Allan W. Eckert, ISBN 0471133973
Internet Resources:
Boulder, beedictionary.com
Koroit Opal News : koroit.blogspot.com
Smithsonian National Museum of Natural History
Materials
Wire
WireJewelry Madagascar Stone Mix Rough - Large Natural Gemstones in 1.5 LB Bag
E6-100R
- Lesson Quantity: 1.00 pieces
- Purchase Quantity: 1.00 each
- Price: $21.91
- Gold Club Price: $16.43
Beads
Cabochons
Tools
WireJewelry - Ultimate Wire-Pliers Jewelry Pliers with Case, Set of 5
G15-20
- G15-20
- Lesson Quantity: 1.00 pieces
- Purchase Quantity: 1.00 each
- Price: $170.72
- Gold Club Price: $128.04
Bench Tools
Supply Detail
loading...
Change Metal:
This Article requires:
Purchase quantity:
Price: $
Gold Club Price: $
Purchase quantity:
Price: $
Gold Club Price: $
- Category: General Education
- Technique(s): General Education
Dale Armstrong
Other Articles by Dale Armstrong
Getting Twisted - Jewelry Making Tools
How to Price Your Wire Jewelry
How to Measure Gemstones for Settings
Cool Anklets are HOT
Inspiration Comes from Everywhere and Every Thing
Wire Jewelry Display and Booth Ideas
Where to Sell Your Wire Jewelry
How to Choose Wire Temper for Making Jewelry
What Gauge of Wire Should I Use to Make Jewelry
What's a Cubic Zirconia Stone
Rockhounding - A Beginner's Guide
What Shape of Wire Should I Use to Make Jewelry
Gem Profile- Bloodstone
Gem Profile- Picture Jasper
Gem Profile- Patterned Jaspers
Gem Profile- What is Jasper
Gem Profile- Quartz Introduction
Gem Profile- Wishful Turquoise
Gem Profile- Amethyst
Gem Profile- Fluorite
Gem Profile- Obsidian
Gem Profile- Rose Quartz
Gem Profile- Smoky Quartz
Gem Profile- Citrine and Ametrine
Gem Profile- Labradorite
Gem Profile- Rhodochrosite
Gem Profile- Moonstone
Gem Profile- Prehnite
Gem Profile- Jade
Gem Profile- Amazonite
Gem Profile- Corundum
Gem Profile- Quartz with Inclusions Part 1
Gem Profile- Quartz with Inclusions Part 2
Gem Profile- Aventurine
Gem Profile- Macrocrystalline Quartz
Gem Profile- Tiger Eye
Gem Profile- Fire Agate and Iris Agate
Gem Profile- Amber
Gem Profile- Ruby Zoisite
Gem Profile- Ruby Fuchsite
Gem Profile- Charoite
Gem Profile- Moldavite
Gem Profile- Ammolite
Gem Profile- White Precious Opal
Gem Profile- Opalized Fossils
Gem Profile- Black Precious Opal
Gem Profile- Pyrite
Gem Profile- Opal Introduction
Gem Profile- Beautifully Colored Jasper
Gem Profile- Common Opal
Gem Profile- Lapis Lazuli
Wire Sculpture Expert Dale -Cougar- Armstrong Interview
The premier place for all your jewelry making needs. The best in wire, tools, cabochons, gemstone beads and more. As well as a superior resource for educational support to help build your jewelry making skills and techniques.
Connect With Us
® 2007 - 2026 Wirejewelry.com Powered by ClaimTheWeb Cart