How is Opal Formed? What are the types of Opal? Where is Lightning Ridge? What is a Triplet? All your questions are answered here!
Q.Do you use Australian Gold?
Absolutely! One of the biggest problems with online sales is there is a very common practice to advertise pieces as ‘gold’ when the small-print (which is often difficult to find) reveals that it is actually gold-plated! This is a huge risk online! Our 18 carat Gold (75% Gold) is genuine! https://vimeo.com/270795844
Q.What is your customer service policy?
To ensure that our customers are completely satisfied, as part of Australian Opal Cutters’ customer service policy we will gladly repair goods or replace goods, at no cost to the customer, for defects in materials or workmanship faults for up to 2 years from the original date of purchase.
Our liability under this warranty is subject to Australian Opal Cutters master jeweller, who has extensive knowledge and experience with jewellery. We check to ensure that a defect was caused by defective materials or workmanship faults, and was not caused by, or substantially contributed by other factors, or circumstances beyond our control. Circumstances that could void our warranty include items such as repair works carried out by a jeweller other than us, accidental or malicious damage, or any neglect or misuse of the goods (as examples). https://vimeo.com/270795825
Q.Will my Rhodium Plating “wear off”?
Rhodium plating is very durable. It is incredibly expensive and beautiful. We offer our warranty and service guarantee with all plating in that we will re-plate the item for life FOR FREE! (rhodium plating can cost up to $200 USD). https://vimeo.com/270795807
Q.How valuable is Pearl?
The Cartier building in New York was originally purchased through a string of Pearls. From the origins of history Pearl has been considered the “Pearl of Great Price.” Some of the values recorded throughout history are staggering, literally worth billions of dollars, using Pearls to even finance wars. The famous story of Cleopatra defeating Marc Antony at the “most expensive dinner in history” through the dissolving and drinking of a fabulous Pearl is an example of this! https://vimeo.com/270795789
Q. What is Synthetic Opal?
Man-made, lab created, treated and cheated gems are a massive problem. These are everywhere! The biggest problem is that the tests to check them are sophisticated and expensive. Traders will always want to make a “quick buck” and as the trend for “throwaway” jewellery increases, we will only “Sell you what we tell you.” https://vimeo.com/270795774
Q.Do you guarantee your hallmarking?
YES! We absolutely guarantee our hallmarks. If a piece were to inadvertently slip through with the wrong hallmark this would be a major failure on the part of our quality control and would be something we would move very quickly to resolve! https://vimeo.com/270795763
Q.Why don’t you sell Ethiopian Opal?
The Ethiopian Opal comes out of the ground looking like a brown beer bottle and requires substantial treatment to get it to show colour. The chemical treatment is effective but is not permanent. We have been contacted by numerous customers who have suffered the shock of this treatment being reversed. This is a problem that the world bank suggests goes right back to a failure in policies set by the Ethiopian government. The customer is often not told about this….and this is the problem. https://vimeo.com/270655155
Q.Do you manufacture in China?
The manufacturing industry in some countries goes back thousands of years. It is often either a form of “prejudice” to say that a country is “inferior” as a producer. For example the CEO of Patek Phillip watches has stated publicly that the best movement in the world is a Seiko movement from Japan but (at $1,500) these will never achieve the $50,000 price of a Swiss watch?!?!?! What people should be upset about is if a person is abused, or exploited in the manufacture of the product (such as the Child slave labour cutting diamonds in Surat India). It is not surprising that some of the best jewellers in the world are from India and China. https://www.thetimes.co.uk/article/the-worlds-five-best-jewellers-flxc8m32fb8 https://vimeo.com/270624596
Q.Is it safe to buy Opal Online?
We value integrity. We live in a world where banks are telling lies and stealing from customers. The original jewellers were bankers and the decline in morality may be the trend but it is not our trend. People are doing research and we are really excited that people are doing the checks online, researching the reviews and making sure that they get the facts! https://vimeo.com/270795799
Q.Do I have to Pay Duty?
Loose gems are basically a duty free item anywhere in the world. The rationale behind this is that someone is going to get a job back in your home country setting up the gemstone into a piece of jewellery. https://vimeo.com/270624564
Q.What is The “portability”?
The diamond industry is famous for being a transferable source of portable wealth. It is very difficult for customs agents to discern a million dollar ring on the finger of a traveller and using this method billions of dollars circulates through the worlds airports in a manner that would be impossible if it was “suitcases full of cash.” Diamonds are very much a means of cash transfer “under the radar.” https://vimeo.com/270624773
Q.Are Opals used as contraband?
Pliny the elder spoke about the value of Opals in eons past. Marc Antony wanted the Opal but Nonius would not give it up and fled Rome to keep his Opal and left his property, wife and family behind. This was Hungarian Opal which is far inferior to the Australian Black Opal. https://vimeo.com/270624494
Q.Does the Opal Industry respect Aboriginal Land Rights.
Native title has had a massive impact on the Australian Opal industry. In the Boulder Opal industry specifically Native title has affected the method, procedure and process by which the miners operate. A direct result of the native title legislation is that miners are now required to gain permissions from the council elders to mine what was once crown land. The negotiations may take many years to secure a native title agreement on a lease. https://vimeo.com/270624620
Q.Is Opal Unlucky?
Opal is really starting to gain momentum all around the world as the “Queen of Gems.” This incredible position is growing despite the alleged efforts of De Beers to promote an “Opal is bad luck” myth. The allegation made against De Beers (by some) is that Sir Walter Scott was commissioned to write the book “Anne of Guerstein” by De Beers where Opal was presented as a gem of bad luck. This is the only place in history where this statement occurs! A book commissioned by Opal’s biggest competitor…the diamond industry! https://vimeo.com/270624749
Q.Are you "Royal Jewellers"?
Yes! We have had some wonderful commissions by the Australian Monarchists league Prince William, Catherine and Camilla. We have had the wonderful privilege of providing an amazing Boulder Opal “split” to Prince William as a gift and have now got one half of the Opal in Kensington Palace and the other in our Pitt Street showroom in Sydney! https://vimeo.com/270624507
Q.Is Opal a “diminishing resource’”?
No-one really knows how much Opal is potentially hidden in the Australian Outback. What we do know is that it is incredibly difficult to find and only occurs in tiny pockets. Opal is, and hopefully will always continue to, form new deposits…but where they are hidden is the mystery! https://vimeo.com/270624714
Is Opal appreciating in value?
Global demand is growing but the supply is decreasing. Basic economics tells us that the result will be a net increase in value. The local Australian customer has (unfortunately) not had a great deal of exposure to the incredible colour and pattern of Australian Opal, but this is changing! Markets like China is also increasing the demand because Opal is so unique, making each jewellery piece eminently collectable. https://vimeo.com/270624733
Q.Is cutting Opal difficult?
It depends on the type of Opal being cut. White Opal is much easier to cut than Black or Boulder Opal because the Opal contains more colour through the ‘rough’. Crystal Opal can be incredible as you can (in rare instances) find pieces that are ‘skin-to-skin’ which is colour bars that are right through the Opal. Black Opal is extremely difficult to cut because the colour is difficult to find and often elusive. https://vimeo.com/270624700
Q.Is buying Rough Opal risky?
Buying Rough Opal is truly speculative and unfortunately the risks are immense. It takes many costly mistakes to be able to determine what hides inside a rough opal parcel! https://vimeo.com/270624645
Q.What is Dark Opal “Rough”?
This is where the Opal has a distinct grey base tone on the “N-Scale”. Dark Opal is from one of the few Black Opal fields and will have a distinct grey base tone. When the colour is found in these they can be often as brilliant as the best Black Opals (but often substantially less expensive) https://vimeo.com/270624919
Q.How Did you get started in the Opal trade?
From a very humble beginning as a jewellery wholesaler with his father, Graeme Blaiklock has been involved in all areas of the Opal industry. While trends and traditions have changed the love, passion and commitment to this gemstone has not! https://vimeo.com/270624858
Q.Do you guarantee the quality of your Silver?
Our silver is tested by sawing a sample piece in half. You have to get inside the metal to check the quality and percentage of silver in the alloy. The hallmark 925 will always contain 92.5% pure silver in the allow and we need to make sure this is always the case. The Rhodium plating is an additional step to add a brilliant finish to your piece. https://vimeo.com/270624578
Q.Can you use Diamond technology to cut Opal?
Opal cutting is a very traditional process. Every Opal is hand-cut and there is no use of sophisticated cutting machinery. There are a number of steps involved and we have a very unique experience in the Sydney store where we invite guests to come and experience Opal cutting first hand. This is a unique experience and one that is truly enjoyable! https://vimeo.com/270624547
Q.Are you ‘world leaders’ in Opal?
With over 80 years of combined experience would you be considered world leaders in Opal? https://vimeo.com/270624530
Q.Why is Opal called the “best kept Secret”?
Q.Why are you so passionate about Opal?
Q.Where is my Opal from?
The provenance of Opal is (as with many other gemstones) fairly broad. There is no ‘block-chain’ provenance in place to define an actual location (for example Mehai Opal will generally produce Opal that will crack, and Mintabie Opal is often distinct in its appearance and colour). Gem Black Opal will be from Lightning Ridge NSW, White Opal is generally from Cooper Pedy and Boulder Opal from Winton in Queensland. The fields we have found the best colour are the “Coochran Run” and “Three Mile”. https://vimeo.com/270624803
Q.What is “vertical Integration”?
An Opal can pass many hands from the miner, to the cutter, the runner to wholesaler then over to the manufacturing jeweller then the retailer. At each stage there is a profit margin added. “Vertical integration” is where you purchase the Opal from one person who has cut out all of the middlemen…like us! https://vimeo.com/270624789
Q.Do I have to pay “duty” on my Opal?
Loose gems are basically a duty-free item anywhere in the world. The rationale behind this is that someone is going to get a job back in your home country setting up the gemstone into a piece of jewellery. Each country usually has an ‘import duty-free threshold”. https://vimeo.com/270624564
Q.How is Opal Mined?
It is a very expensive process. Normally someone who has a ‘claim’ will partner with someone who has a ‘rig’. They will drill a spot hole to find ‘trace’. The miner has to drill literally hundreds of holes, an average of 1,500 drill holes to find a good deposit of Opal. The leaseholder has a limited time to actually find the Opal and start mining so it is very stressful. https://vimeo.com/270624666
Q.Is Opal more valuable than Diamond?
Black Opal with a ‘named pattern’ is arguably the most valuable commercially available gemstone on earth and there is a suggestion that this form of Opal is up to 5000 times rarer than diamond! https://vimeo.com/270624733
Q.Is Quality Worth Anything Today?
Price you forget but quality you have got to live with! A thing of beauty is a joy forever! The pain of paying a slightly higher price is nothing compared to the pain of living with poor quality. The tragedy with low price jewellery is that it will inevitably fail at some point! With Australian Opal Cutters You pay for quality, not simply because the piece has a ‘brand-name’. https://vimeo.com/270655127
Q.What is The “Cheap side Hoard”?
The Jewellery trade has been a melting pot for millennia! The ebb and flow of gems, gold, trade is an insight into how advanced the Jewellery trade has been for so many centuries. https://www.gia.edu/gems-gemology/fa13-cheapside-hoard-weldon https://vimeo.com/270655174
Q.Do Hotel Concierges Recommend you?
We want to thank all of you continuing to send your guests into Australian Opal Cutters and Australian Pearl Divers, we know that you want your customers to have the best experience they can in Sydney…this is an absolutely unique, authentic experience that your guests will love. This is an amazing experience that is genuine, trustworthy and an experience that your guests will THANK YOU for sending them in! https://vimeo.com/270655207
Q.Is Pearl the June Birthstone?
What are your Customer Service “Values”?
Good “Old Fashioned Service” is what we believe in. The old adage “Do unto others as you would have them do unto you” are words that we live by! What makes the difference is that we believe in our product and in serving you in a way that invites you to return and tell others! https://vimeo.com/270655140
Q.Are there any Secrets to Buying Rough Opal?
The Opal miner knows exactly what is inside the parcel and will often sell rough Opal only because they know what is inside. The biggest ‘risk’ is where the ‘rough’ Opal looks great on the outside but when you cut it is not as impressive (because of cracks and/or a change in the colour bar to make it far less brilliant when ‘opened up’. https://vimeo.com/270624882
Q.What is “Andamooka Opal”?
Opal from a Mining Area in South Australia. Producing Crystal Opal and treating matrix opal
Q.What is “Assembled Opal”?
Opal that has been glued together, also known as mosaic, composite or assembled opal
Q.What is “Boulder Opal”?
Opal Formed in cavities and cracks of ironstone, usually from Queensland, Australia
Q.What is “Black Opal”?
Naturally occurring rare and valuable solid opal formed in Iron oxide found in Lightning Ridge in Northern NSW.
Q.What is “Black Crystal Opal”?
Solid black opal which is transparent due to little or no iron oxide on the back. Viewed from the top, it compares at least with N3 in darkness rating
Q.What is “Blue Opal”?
Solid black opal with the common blue covering the entire stone. Sometimes called “blue opal”, “Blue on black”. There are also forms of ‘fire Opal’ that have a light blue base colour or "Peruvian blue opal" mined in the country of Peru in South America. Although this stone is common opal that does not have a play-of-color, it is nevertheless very desirable because of its beautiful blue bodycolor.
Q.What is “Cabochon”?
A precious stone of convex hemispherical or oval form, polished but not cut into facets - The rounded surface of a cut stone.
Q.What is “Calibrated” Opal?
Opals cut to standard dimensions (usually measured in millimeters)
Q.What is a “Carat Weight”?
This is a Standard to express the weight of gemstones. One carat equals 0.2 grams. Gem quality black opals can sell for more per carat than diamonds!
Q.What is “Chinese writing” pattern?:
A Type of opal pattern with crisis crossed strokes of colour looking like oriental Chinese characters
Q.What is “Clarity”?
The degree of transparency and clear colours and patterns of an opal
Q.What is “Common Opal”?
Opal which does not show any play of color. Potch is another name for common opal and common opal is found on the bottom of most opals
Q.What is “Crazed” Opal?
Opal with a multitude of little lines that look like cracks. If they are actually colour bar separators then they are “Crazing” (As opposed to cracking). This is a natural phenomenon where iron oxide “lines” actually separate the Opal colours.
Q.What is “Crystal Opal”?
Transparent/translucent opal. Sometimes mistaken for “Light opal” found in Coober Pedy in South Australia.
Q.What is Opal “Fire”?
Any Opal Colours which can be seen brightly even in semi-darkness or in the shade
Q.What is Fire Opal?
"Fire Opal" is a term used for colorful, transparent to translucent opal that has a background color of yellow, orange or red. It may or may not exhibit "play-of-color." The color of fire opal can be as vivid as seen in the three stones shown here.
Some people are confused when they hear the name "fire opal." They immediately expect the "play-of-color" found in precious opal. The word "fire" is simply referring to the red, orange, or yellow background color. The reason for the confusion is that in Australia the “fire” in the Opal is often a reference to the brightness, hue and saturation!
Fire opal might exhibit play-of-color, but such a display is usually weak or absent. Fire opal is typically a specimen of opal with red-spectrum background color….and in Australian Opal the ‘fire’ is any colour that ‘jumps out’ at you when you use the “miners test” (cup the Opal in your hand, take it away from the bright light and you will see if it has ‘fire’ (brightness/hue) in low light.
Q.What is Precious Fire Opal?
This opal from Ethiopia has the orange-red body color that defines the category of “fire opal,” but it also contains play of colour, electric green to purple, making it a “precious fire opal.” Much of the Ethiopian opal currently being produced falls into this category however there is no test available to determine when an Ethiopian Opal has been treated with resin or dye to enhance the colour.
Q.What is “Free-form” Opal?
A naturally shaped opal - something other than an oval or round shape egg. Boulder opal cut generally in rectangular or triangular shapes to avoid unnecessary colour wastage
Q.What is a “Nobby”?
A Nodule of rough opal almost exclusively from Lightning Ridge
Q.What is a “Picture Stone”?
Highly valuable opal which shows a distinct image other than a pattern
Q.What is “Potch”?
Opal without any colour, also called Iron Oxide
Q.What is “Rough” Opal?
Opal in its natural state; as it comes out of the ground
Q.What are “Rubs”?
Opal pieces initially shaped with waste material/sand removed but not yet cut and polished
Q.What is Precious Opal?
“Precious Opal” is a term that is used when the Opal has ‘fire’ (colour) and is valuable.
Most precious opal to date has been mined in Australia as this is where the colours and patterns found are the most intense.
Ethiopia and Mexico are secondary sources of precious opal, however the colours are usually either treated and dyed or a much more subdued tone. Precious opal is also mined in Brazil, the United States, Canada, Honduras, Indonesia, Zambia, Guatemala, Poland, Peru, and New Zealand.
Q.What is Common Opal?
"Common opal" does not exhibit "play-of-color." It is given the name "common" because it is found in many locations throughout the world. Most specimens of common opal are also "common" in appearance and do not attract any commercial attention.
However, some specimens of common opal are still attractive and have enough colour to deserve setting into jewellery.
Q.What is Black Opal or Dark Opal?
"Black opal" is a term used for opal that has a dark body-tone color, often black or dark gray. The term is also used
Q.What is Pink Opal?
Opal also occurs in shades of pink, common opal mined in Peru. The range in color is from nearly white, through carnation pink, through lilac.
Q.What is Morado Opal?
"Morado" is the Spanish word for "purple." Some common opal with a purple bodycolor produced in Mexico has been given the name "Morado Opal.".
Q.What is Harlequin Opal?
"Harlequin opal" is a name given to an opal with patches of color in the shape of rectangles or diamonds.
Q.What is Contra-Luz Color Play?
"Contra-Luz" is a name used for a color-play that is visible when the light source is behind the stone. This effect only occurs in stones that are transparent or nearly transparent.
Q.Pinfire Opal (also known as “Pinpoint” Opal)?
"Pinfire opal" is a name used for opal that has pinpoints of color throughout the stone.
Q.What is Cat's-Eye Opal?
Rarely, opal will display chatoyancy, the optical effect that produces a "cat's-eye" across the surface of a stone. In these opals, a thin line of bright light is reflected from a parallel network of needle-shaped inclusions within the gem.
The line, or the "eye", tracks back and forth across the dome of the stone as the stone is moved, as the light source is moved, or as the head of the observer is moved. Cat's-eye opal from Madagascar shows chatoyancy that is produced by hundreds of parallel rutile needles that span the width of the stone and reflect a line of light much like the line of light that is reflected from the surface of a spool of silk thread.
Q.What is Andamooka Opal?
Andamooka is one of the early mining districts of South Australia. Commercial production began there in the 1920s. The area is famous for its matrix opal.
Q.Why is Australian Opal Better?
Australia has been the world's leading source of opal for over 150 years. It has produced ten times more opal than the rest of the world combined. Numerous world-famous localities in the country produce distinct varieties of opal. Precious, black, matrix, water, boulder, jelly, common, and other types of opal are all found in Australia.
Q.What is Coober Pedy Opal?
Coober Pedy is a small town in South Australia that was first settled in 1916 when mining for opals began. It was one of the early prolific producing areas and has earned the nickname of "Opal Capital of the World." Coober Pedy is famous for producing white base-color opals, and production has continued uninterrupted since 1916.
Q.What is Ethiopian Opal?
Gem-quality opal from Ethiopia began entering the market in significant amounts starting in 1994. Since then, additional opal deposits have been discovered that would be large enough in size to take significant market share away from Australia, which has supplied nearly 100% of the opal market for over 100 years. Precious opal, fire opal, and very attractive common opal are all being produced in Ethiopia. They initially were becoming more abundant in the gem and jewelry market and more popular with consumers until customers became aware (over time) that the treatment processes with Ethiopian Opal (smoking and dying to increase the colour) can be reversed when the Opal comes into contact with household cleaning chemicals. When the Opal treatment is reversed a beautiful, bright multi-coloured gemstone will return to its original brown/grey base tone with very little colour visible.
Q.What is Honduras Black Opal?
Honduras is well known for producing a black, basalt-matrix opal that contains tiny vesicles filled with play-of-color opal. Most people who know opal will understand exactly what you are talking about if you use the term "Honduras Black Opal."
Q.Where is Lightning Ridge Opal?
Lightning Ridge is a town in North Western New South Wales (near the Queensland border in Australia). An area that has become world-famous for its deposits of black opal. More black opals have been produced at Lightning Ridge than at any other location in the world.
Q.What is Mexican Opal?
Mexico is famous for being the world's most important source of fire opal. Mexican fire opal is known for having the most saturated and purest hues. Mexican fire opal is cut into beautiful cabochons, and much is cut into brightly-colored faceted stones. Mexico also produces beautiful precious opal. A unique cutting style, known as cantera, yields cabochons that display pockets of fire opal in their rhyolite matrix. The cabochons shown here were cut from fire opal found in Mexico. They all have a bright red, orange or yellow background color.
Q.What is Louisiana Opal?
"Louisiana opal" is a quartzite cemented with precious opal that has been mined in Vernon Parish, Louisiana. On close examination you can clearly see quartz grains with the spaces between them filled with a matrix of clear cement that produces a play-of-color in incident light. It is a stable material that can be cut into cabochons, spheres and other objects. Some of the material is brown but it also occurs in a gray to black color that makes the play-of-color easier to see.
Q.What is Peruvian Opal?
Peru produces some of the world's most beautiful common opal. It is not play-of-color opal; instead, it is common opal of uncommon color. Opal mines in Peru yield common opal in pastel colors of blue, green, and pink. Peruvian opal is also used to make beautiful cabochons and tumbled stones.
Q.What are “Assembled” or “Composite Gemstones Stones”?
Most cut opals are solid stones. The entire stone is cut from a single piece of rough.
However, some opal rough has very thin but brilliant layers of play-of-color material. Some artisans cut the stone down to the thin color layer and glue it to a base of obsidian, potch, basalt, or plastic - then cut a finished stone. These two-part stones are called "opal doublets".
To protect the fragile opal from abrasion and impact, some artisans glue a transparent cap of quartz, spinel or other transparent material onto the opal. This produces a three-part stone, called an "opal triplet"
Q.What is an Opal Doublet?
Opal doublets are assembled from a thin layer of precious opal glued to a backing of host rock (most often Boulder Opal). On the side view you can clearly usually see the very straight "glue line" between the two materials. If a Doublet is mounted in a setting with a cup bezel, it might be impossible to tell if it was a solid opal or a doublet Opal.
Q.What is an Opal Triplet?
Opal triplets are produced by sandwiching a thin layer of precious opal between a backing of black obsidian and a cover made of clear synthetic spinel or quartz. The clear top acts like a magnifying lens and enhances the appearance of the thin precious layer. The black obsidian back provides a contrasting background that makes the play-of-color in the precious layer more obvious. If you look very closely at the edge of the gemstone stone, you will see a tiny line of color that is the edge of a thin slice of precious opal. If the Opal is set into a bezel you can carefully look through the surface at an angle to see if it is quartz (this is a fairly difficult detection method as the colour usually reflects very thoroughly throughout the quartz crystal cap)
Q.What is Natural Opal?
Because of opal's beauty and desirability, people have been producing materials that look like opal for nearly a century. A person with a little experience can easily recognize most of the "look-alikes." "Natural opal" is the name used for genuine opal that has been mined from the Earth. It is genuine opal made by nature and not by humans.
Q.What is Synthetic Opal?
"Synthetic opal" or "lab-created opal" or "lab-grown opal" are some of the names used for opal that has been made by humans. These opals are made from materials that have the same chemical composition (hydrated silicon dioxide) as natural opal. They can have spectacular play-of-color and a beauty that rivals some of the best natural opals.
Synthetic opal has been made since the 1930s. An untrained person might not realize that this opal is synthetic, but trained gemologists can usually tell synthetic opal from natural opal by examination with a loupe or microscope and sometimes with their unaided eyes. However, some synthetic opals are so convincing that trained gemologists must send suspect specimens to a laboratory for positive identification.
Q.What is Imitation Opal?
"Imitation opals" are often made from plastic or a glassy material that is not silicon dioxide, and their play-of color is not produced by light passing through an array of tiny spheres. They sometimes called "opalite" when sold in stores. These materials can have a very attractive appearance that looks very similar to opal. They are legitimate products if they are not advertised or sold in ways that inexperienced buyers will assume that they are buying natural opal.
Q.What is Opalized Wood?
Opalized wood is a type of petrified wood that is composed of opal rather than chalcedony or another mineral material. It almost always consists of common opal, without play-of-color, but rare instances of petrified wood composed of precious opal are known. Petrified wood composed of opal is often thought to be composed of chalcedony because many people do not know that petrified wood can be opaline. These two types of silicified wood can be easily separated by testing their hardness, specific gravity, or refractive index.
Q.What is Mookaite Opal?
"Mookaite" is the trade name for an opaque gem material with spectacular color patterns that is mined in Western Australia. Gemological testing identifies most mookaite as a chalcedony. However, some mookaite has the refractive index and specific gravity of opal.
Q.What is Fluorescent Opal?
Most opal will glow or fluoresce weakly under an ultraviolet lamp. However, some specimens exhibit a spectacular fluorescence. Mossy common opal rough from Virgin Valley, Nevada fluoresces a brilliant green under UV light.
Q.What is Opalite?
Opalite is a name given to an impure variety of common opal that can contain plumes, moss or other inclusions. The name "opalite" can be confused with plastic or glassy materials - imitation opals - that are sold under the same name.
Q.What is "Water Opal" or Hyalite?
Some opal does not exhibit a "play-of-color," does not have a base color, and does not have a bodycolor like most common opals. But this material is still opal called "water opal" and "hyalite."
Q.Are there Opals on Mars?
In 2008, NASA's Mars Reconnaissance Orbiter has discovered a number of opal deposits on Mars. The ground the surface in an impact crater was found to be covered with hydrated silica rock debris that we would call "opal." Mars researchers have also identified layers of opal exposed in the outcrops of crater walls. Since opal is a hydrated silicate its formation requires water. So, the discovery of opal on Mars is another evidence that water once existed on the planet. Image by NASA.
Q.Which Field Did My Black Opal Come From?
There are over 200 Opal mining fields in Lightning Ridge, however most of Australian Opal Cutters Black Opals come from the following mines:
One of the only ‘Walk-In’ mines at Lightning Ridge, most of the precious Opal found in this area was recovered from the main workings over an area of only 120 metres by 30 metres! Visitors can walk through the mine from 9am to 5pm daily with self-guided tours or coach tours.
In the 1930’s, miners extracted good quality Opal from five claims at Deep-Four Mile, with the deepest shaft spanning over 28.5 metres.
Sinking at this site ranged from 1.2 metres to 12 metres, with lenses up to 2.7 metres thick still present, producing good quality precious Opal. In some of the shafts three Opal bearing lenses at 3.6 metres, 6.9 metres and 12 metres were intersected.
Discovered in 1973, this mine is thought to be one of the most productive mines in the area. It was estimated that eight claims produced over $3,000,000 worth of Opal over two years. Mining techniques used on site over the years began with large-scale open-cut mining, followed by underground mining.
New Chum and Old Chum:
A Opal stone of 100 carats was recovered from the New Chum area of this site and Opal float was found in gravel on the side of the hill in the Old Chum area.
New Rush (New Nobby):
Mined in the 1960’s with a maximum shaft depth of 12 metres, this site returned precious Opal, which resulted in a rush to the area and the sinking of about 100 shafts.
One of the most worked fields still being worked today, shafts stretch to 12 metres deep on the crest of the hill. Potch was found interspersed with Opal in this area.
The exact location of this area is uncertain; however, it is known to be closed to McDonald’s Six Mile. Only two claims produced significant quantities of Opal in this area and much of the Opal was in the form of big Black Nobbies.
As the name suggests, this field is quite shallow, with a depth of 0.3 metres to 3.6 metres. Good quality Opal has been recovered at this site and consisted of opalised bivalves.
The Old Nobby:
One of the first shafts on the Lightning Ridge field was sunk at Nobbys and Opal was initially found in the gravel at the foot of the ridge. Although the rocks are extremely difficult and hard to work, a considerable amount of Opal has been recovered from a lens depth of 6 metres.
The Three Mile:
One of the most famous and overworked mines, this field has peaked at over 1,000 people engaged in Opal mining there at one time. By far one of the most productive areas on the field, large-scale open cut mining has been carried out in recent years.
The Six Mile:
Also known as McDonald’s Six Mile, the depth to the Finch clay facies ranges from 9 metres to 12 metres on the crest of the hill and 1.8 metres at the base of the hill, with the best Opal found deeper in the ground.
Thorley’s Six Mile:
This field was first mined in 1902 from a range of 6 to 12 metres and then rediscovered by miners in the 1970’s, as the field continue to produce high quality Black Opal.
Q.How is Opal Mined?
Prospecting is the term used to describe opal mining. Potential miners need to apply for an “Opal Prospecting License” or Mineral Claim before they can begin prospecting. It is important that potential miners remember that prospecting is quite different from mining.
Prospecting licenses are allowed over larger areas and are quite easy to obtain in comparison to mineral claims, which often require bonds. Generally, there are 50 to 100 Opal Prospecting Licenses that are approved annually. There are four defined prospecting areas in the Narran-Warrambool reserve, which were set aside to help preserve the tradition of small prospectors rather than continuing to grant large mineral claims. It is important to note that prospecting cannot be undertaken in national parks or wildlife areas.
Opal prospecting can be a tiring job, with lots of drilling and picking in underground mines, which are held up by shafts. Today, there are a number of different ways prospectors can recover Opals:
Q.What is Shaft Sinking?
Prior to the establishment of the drill in 1987, shaft sinking was the most popular method for prospecting opal fields. Unfortunately, sinking shafts by hand was expensive and time consuming.
Q.What is Auger Drilling?
The introduction of the drill not only quickened the mining process but also offered a more cost-effective technique to sink shafts. The nine-inch diameter auger drill helped miners test for sandstone prior to sinking a shaft, rather than working blindly in an area.
Q.What is Percussion Drilling?
Percussion drilling is similar to Auger drilling, however it is much more precise because it creates smaller holes and is consequently a more efficient way of finding and testing samples.
Q.What is Sirotem Mining?
This modern mining technique is by far the most efficient means of testing a large area of ground. By using electrical currents to measure the rock’s electric resistance, miners can find where faults or sandstone could exist in the area.
Q.How Much Does it Cost to Mine Opal?
Gone are the days when all a miner needed was a $20 claim and pick and shovel to mine the area. Today, a deposit of over $250,000 is required to operate a typical open cut mine and at least double that to operate an open cut Opal mine. Due to this, several claims are required to join together, which often proves difficult.
Furthermore, new regulations require miners to undertake a $2,000 Opal mining course, which teaches them about first aid, electrical problems and technical safety procedures. Miners must also apply for an Opal mining claim from the ‘Department of Minerals’ and must abide to strict environmental contentions, which include replanting vegetation on the site following the claim expiration date. Over the years, the price of this claim has staggered from $435 to an astounding $1230. In 2013, ABC News released an article that detailed the harsh reality and costs associated with living in Lightning Ridge as a miner, which you can read here.
It is not easy for ‘outsiders’ to purchase and establish an Opal mine in the area, as Opal mines for sale are rare and usually sold within the community. Many of the best Opal mines are purchased under a profit share, rather than being sold entirely. This means that the owner can still receive a percentage of profit from the Opals mined by local workers.
Even life in Lightning Ridge itself comes at a high price. Everyday luxuries are rarities and petrol is almost double the city price. Many miners have had to take up another job at local coal mines, to ensure a steady cash flow. Yet even though the life of a Lightning Ridge miner can be difficult, it can also prove to be rewarding, with many miners returning year after year.