All About Opals

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Archive for November 4th, 2006

Opal Jewelry Part 3

Saturday, November 4th, 2006

Opal Jewelry Part 3Part 3 of a 3 part series on Opal Jewelry

You don’t need to know all about opals to buy one but there are some things to watch for when buying opals includes firstly that the opal is genuine.

Opal Certificates

All opals should come with a certificate authenticating the genuineness of the opal. This applies to opals set in rings and other jewelry and not just loose opals as well of course.

Note that there are partially made opals called doublets and triplets. With these, a thin opal is under laid with other material such as crystal or quartz and overlaid with another transparent substance. Also ironstone is often used as a backing.

Checking Opals

When you are inspecting an opal always check the opal for the following:

Does it have a white body tone or look transparent? If so this is a good sign. Doublets and triplets are dark in tone so if it is all white in body tone it is more than likely a genuine article.

The side should not have any visible “layers” A triplet usually has a thin opal between two other materials the top being transparent.

Check the back also to see if it feels like hard plastic. Is there something glued to the back of the opal? There should be nothing on the back of an opal (bounder opals are an exception, see boulder opal).

In addition natural genuine opals will seem irregular and not perfect around the circumference which an artificial opal is. You can feel irregularities and bumps if you run a sensitive finger around the opal.

If the opal is already set in jewellery also be very careful as it is not always possible to see the back. If you cannot see the back of the opal it is quite possibly not a natural one. Even opal experts can have a hard time checking this.

Check out real opals from an opal shop before you buy. Find out what a real opal looks and feels like. Gain some familiarity with opals, It always pays to become educated and do your due diligence before you buy.

Opal Experts

If you have an opal you are not sure about take it to a gemologist or an opal expert. There are some listed in the links section of this website.

lastly always only buy opals from someone who has gemological qualifications and or at least is a member of a gemological association. Reputable dealers will be responsible and are answerable to the association to which they belong. Also ensure that you get a certificate of authenticity for every opal you buy and a guarantee that if it is not what was advertised then you can return it.

Following the above will go a long way to ensuring that you buy genuine opal jewelry and have many year of enjoyment with it.

Opal Jewelry Part 2

Saturday, November 4th, 2006

Opal Jewelry Part 2Part 2 of a 3 part series on Opal Jewelry

Characteristics of Opals

Precious opal shows a variable interplay of internal colors and does have an internal structure. At the micro scale precious opal is composed of hexagonal or cubic closely packed silica spheres some 150 to 300 nm in diameter. These ordered silica spheres produce the internal colors by causing the interference and diffraction of light passing through the microstructure of opal (Klein and Hurlbut, 1985, p. 444). In addition, microfractures may be filled with secondary silica and form thin lamellae inside the opal during solidification. The term opalescence is commonly and erroneously used to describe this unique and beautiful phenomenon, which is correctly termed play of color. Contrarily, opalescence is correctly applied to the milky, turbid appearance of common or potch opal. Potch does not show a play of color.

The veins of opal displaying the play of color are often quite thin, and this has given rise to unusual methods of preparing the stone as a gem. An opal doublet is a thin layer of colorful material, backed by a black mineral, such as ironstone, basalt or obsidian. The darker backing emphasizes the play of color, and results in a more attractive display than a lighter potch. Given the texture of opals, they can be quite difficult to polish to a reasonable luster. The triplet cut backs the colored material with a dark backing, and then has a cap of clear quartz (rock crystal) on top, which takes a high polish, and acts as a protective layer for the comparatively delicate opal.

Besides the gemstone varieties that show a play of color, there are other kinds of common opal such as the milk opal, milky bluish to greenish; resin opal, honey-yellow with a resinous luster; wood opal, caused by the replacement of the organic material in wood with opal; menilite brown or grey; hyalite, a colorless glass-clear opal sometimes called Muller’s Glass; geyserite, (siliceous sinter) deposited around hot springs or geysers; and diatomite or diatomaceous earth, the accumulations of diatom shells or tests.

This was part 2 of a three part series on Opal Jewelry

Watch for Part 3 coming soon!

Opal Jewelry Part 1

Saturday, November 4th, 2006

Opal Jewelry Part 1Part 1 of a 3 part series on Opal Jewelry

Australia is the largest producer of opals in the world, producing 95% of the worlds opals for opal jewelry and most of these in Australia are produced at a place called Coober Pedy. The balance come from places such as Mexico, the north of Brazil The US and Africa even.

In 1849 the first Opal blocks were accidentally found on an Australian cattle station called Tarravilla . the first Opal prospectors started in 1890 at White Cliff mining the Opal rocks. And even today the eyes of Opal lovers light up when somebody mentions places like White Cliffs, Lightning Ridge, Andamooka or Coober Pedy: for these are the legendary sites of the Australian Opal fields. The most famous one is probably Lightning Ridge, the place where mainly the coveted Black Opal is found. Andamooka, where Crystal Opal and Light Opal are brought to the light of day, cam boast to be the place where the probably largest Opal was found, with a weight of 6 ,843 kilograms, the “Andamooka Desert Flame”.

Coober Pedy

Coober Pedy, by the way, is a word from Aborigine language meaning “white man in a hole”. This clearly describes how Opal was in fact mined: many Opal prospectors made their home in deep holes or caves in the ground, to protect themselves from the burning heat of daytime and from the icy winds of night time. Usually they worked only with tolls such as pick and shovel. Buckets full of soil, hopefully containing Opal rocks, were pulled up out of the depths of 5 to 40 m deep shafts by hand, for this is the depth of the Opal containing crevices and cavities, which are also mined nowadays.

Being an Opal prospector is still not an easy job, although today of course there are some technical means available, such as trucks or conveyor belts. And still the hope to make the find of a lifetime which will let you live happily ever after attracts many men and women to come to the hot and dusty Australian outback.

What is Opal made of?

The mineraloid opal is amorphous hydrated silicon dioxide, the water content sometimes being as high as 20% but is usually between three and ten percent. Opal ranges from colorless through white, milky blue, gray, red, yellow, green, brown and black. Common opal is truly amorphous, but precious opal does have a structural element. The word opal comes from the Sanskrit upala, the Greek opallios, and the Latin opalus, meaning “precious stone”.
Opal is a mineraloid gel which is deposited at relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, and basalt.

Opal is one of the mineraloids that can form or replace fossils. The resulting fossils, though not of any extra scientific interest, appeal to collectors.

Watch for Part 2 of Opal Jewelry

Fire Opals from Australia

Saturday, November 4th, 2006

Fire Opals from AustraliaFire opals from Australia are a particular type of opal and very popular, but you don’t have to know all about opals to appreciate the fine quality of fire opals available.

95 percent of the worlds opals come from Australia. Most of these from a town called Cooper Pedy in South Australia. Lightning Ridge, a town in New South Wales, a state further north of Australia, is predominately know for its black opals. Opals are also found in the US, Mexico (famous for its own fire opals).

White most opals are either white or “pearl” color and rarer the black as mentioned above, there is also the Australian fire opals. The Australia fire opal is a translucent to semi-opaque stone that is generally yellow to bright orange and sometimes nearly red and displays pleochroism at certain angles.
Pleochroism is an optical phenomenon where due to double refraction of light by a colored gem or crystal, the light is divided into two paths which are polarized at a 90° angle to each other. As the divided light follows different paths within the stone and are traveling at different speeds, they may have the result of differential selective absorption, thus when they leave the crystal they have different colors, making the stone seem to be of different colors. Pleochroism is an extremely useful tool for mineral identification.

Australian fire opals are relatively rare and so command a higher price.

When buying opals ensure you get a certificate that describes the type of opal you are getting. This is important not just for insurance purposes but also for possible resale at a later date.

With a bit of due diligence and plenty of browsing it is possible to find a very nice fire opal from Australia that will look absolutely splendid

Opal Earrings Part 1

Saturday, November 4th, 2006

Opal EarringsOpal earrings can look very striking, especially when the opals are really good quality ones with the characteristic flash of colors in the opals.

The type of opals used in earrings will depend on the fashion occasion and what looks best on you with regard to fashion, skin coloring and other factors.

These can include the white opal, black opal, boulder opal as well as the fire, crystal and matrix opals. (More information about each of these is available the links on the right)

Also the size of the opals can make a difference.

In terms of cost buy what your budget can afford and get the best possible quality for your money. Read this whole site so you get to know something about opals. Browse around and look at many opals and even get to feel and touch them if you can. Get some familiarity with opals and you will get to understand them well.

You will then be in a better position to select just the right pair of opals for earrings or just the right pair set already as earrings.

Make sure you get a certificate to show the quality and type of opals and even the estimated value. This is useful for insurance purposes and even perhaps if the occasion arises to sell them at a later date.

Once you have your opal earrings it is good to maintain them well and keep them clean. Only wear then when you need to and store them well when not in use.

Cleaning with warm soapy water and really rinsed well afterwards to get any soapy residue removed from the settings. Then dried completely and stored separately from other jewelery when not in use.

Opal earrings are a great jewelery piece and should last a life especially when they are well looked after.

How to tell one opal from another

Saturday, November 4th, 2006

how to tell one opal from anotherHow can you tell one opal from another? What is the difference between various opals? And why is it important to do so?

Opals are unique in that they are not gems and unlike diamonds or rubies. They are made of an entirely different material but, like many precious stones, have their differences, and these can equate to thousands of dollars so it is wise to have some understanding of opals and the differences between them.

Some of the more common opals available are:
Black Opal
White Opal
Boulder Opal
Crystal Opal
Fire Opal
Matrix OpalThe Black Opal has a dark body tone which causes a brightness of color unmatched by the other opal types. Black Opals are only mined at Lightning Ridge in New South Wales in Australia and considered very rare and are the most expensive of all opals

White Opals, by contrast are almost cream and sometimes called a Milky Opal Being white they do not show the internal color so well as the black and are generally purchased as white opals only. In an excellent quality stone however there can still be seen some color flashing. These can be purchased relatively cheaply although a really good quality one can set you back a few hundred or thousand dollars.

Boulder Opals are different again. These have a solid layer of brown ironstone on the back of the stone. They originate from large ironstone bounders, hence the name, underground.

A Crystal opal can be the same as above but has a transparent or semi-transparent body tone which means you can see through the stone. Crystal opal can have a dark or light body tone hence, “black crystal opal” and “white crystal opal”

A Fire Opal is an American term and describes any opal which has a significant amount of red coloring. Red is the rarest Color in opals, so these are quite valuable. Often confused with a ‘Mexican fire opal’ which is different yet again and displays orange instead of red coloring.

A Matrix opal is where the opal occurs as a network of veins or infilling of voids or between grains of the host rock. A Matrix comprises precious opaline silica as an infilling of pore spaces in silty claystone or ironstone. the matrix opal shows a fine pinfire color in the natural state. very rare also.

It is important to understand and know what you are purchasing and further information is available at the links on the right.

How to care for Opals

Saturday, November 4th, 2006

How to care for OpalsMany people do not know how to really care for their opals resulting in opals that are damaged and drastically reduced in value.

It is very important that one understands how to look after ones opals and keep them in the best condition. This way they will last for years and retain their value.

Firstly of course one should buy quality opals from a good dealer or jeweler. Understanding what is a good opal is most important. It is true that many jewelers do not know much about opals. Going to a jeweler that specializes in opals will help here.

Firstly some dos and don’ts.

You can clean your opal in water but do not use detergents or bleaches. These will ruin a stone as the chemicals can react adversely with the opal and especially with the glue or cement that holds the opal in place. It has happened that an opal has eventually fallen out when the glue has deteriorated and been lost forever.

It is not a good idea to wear an opal if you are gardening or with your hands deep inside a car engine. Although the oil and probably the soil from the garden may not hurt the opal it can easily get scratched, lose its shine and become very dull.

In addition grime and oils can build up around the stone and cause it to look very unsightly. Besides which, if you have a claw setting it is very easy to damage the claws and lose an opal that way as well.

Opals can be re-polished if they get too dull. You can find opal polishers in your city by looking through the yellow pages and there are also many on line. But choose carefully. You would like to see your opal back again when it is done.

Store your opal jewelry when not in use. This will help to keep it in great condition most of all. It is not a good idea to wear opal jewelry all the time. Opals are not as hard as diamonds and can be damaged easily. When storing them, make sure it a cool place. Not under hot lights or near a heater. Opals can crack with too much heat.

It is a good idea to ensure your opals are fully insured. A certificate that establishes the authenticity of your opal and the value and the stone insured for replacement value is a shrewd move.

If you are wearing a opal ring it is a good idea to remove it (and put it somewhere safe such as a purse or pocket, not just on a bench top) when you wash or clean your hands. Rings have been known to slip of fingers especially when rubbed with soap or cream.

Being very sensible and aware when dealing with opals and opal jewelry is the basis of caring for your opals.

Keeping mind the above will go along way to ensure your opals are long lasting and give years of pleasure.How to Care for Opals

Black Opal Rings

Saturday, November 4th, 2006

Black Opal RingsOver 95 percent of all opals come from Australia Boulder opals from Queensland, Crystal opals from Cooper Pedy in South Australia Black opals are found only at Lightening Ridge, New South Wales in Australia. They look very striking if the opal is set in the right sort of ring, Yellow or white gold perhaps or even platinum.

There are various depth of black opals and the really black ones reflect many colors inside. There is more information about black opals in the links to the right.

Looking after opals properly is very important. It is a good ideal not to wear opal jewelery and rings when doing physical work. Opals scratch easily and chemicals, oils and grime can damage the opal. Not only that but the setting, such as the glue or cement or even the claw setting can be damaged resulting in a loose and, heaven forbid, a lost opal. Having ones hands deep in a car engine while wearing ones opal ring is asking for trouble.

Cleaning a black opal ring is quite easy. Wash it in warm soapy water (not detergent) and rinse really well then ensure it is dried completely. Then stored separately away from other jewelry. Opals can scratch easily and storing them with other jewelry such as diamonds means they can be scratched easily.

Looking after your black opal rings well will ensure you have black opals that last for many years and give you much pleasure.

Opal Silver Jewelry

Saturday, November 4th, 2006

Opal Silver JewelryOpal silver jewelry can really look very tasteful. An opal ring, necklace and, very popular, opal broaches, can enhance a dress or clothing very well.

It is important, when buying opal silver jewelry, to ensure that you are getting what you pay for. There are many different types of opals one can have in jewelry and each has a particular look to suit any taste.

Opals need not be very expensive. You can get some very nice opals for a few hundred dollars if you shop around. It pays to do a lot of browsing and get to know opals and what types there are. Also the various sizes, qualities and prices. It does not take long to get familiar and have a good idea of what is good and what isn’t.

The opal should be a genuine opal and have a certificate to demonstrate its authenticity. The most popular is a white opal although sometimes a black opal can be quite striking in the right setting. Boulder and fire opals can also look very striking. Some opals look better in a broach setting while others will suit a ring or a pendant. It is a matter of choice and taste which you prefer.

The silver should be pure silver, 99.99 percent or at least sterling silver (around 95 percent silver) and the setting to hold the opal should be a good firm claw setting rather than a glue setting as glue can deteriorate over time, especially with the various chemicals and creams that are used on the body.

This brings up the point of maintenance. Opal silver jewelry should be well maintained. A regular wash in warm soapy water and well rinsed will keep the jewelry clean. Make sure it is completely dry, gently using a hair drier is good, to remove all water as this may tarnish the silver. Then storing it separate from other jewelry, especially diamonds. Diamonds can scratch the opal and silver and damage them.

When buying opal silver jewelry, keep the above points in mind and you can have a very nice piece of jewelry that will give much pleasure for many years to come.

Opal Necklace

Saturday, November 4th, 2006

Opal NecklaceAn opal necklace can look very nice and set off the shape of the neck very well.

When choosing an opal necklace there are some points it is well to keep in mind.

There are many different types of opal which can be set into a necklace. Also many different prices as well.

The most popular is the white opal. These can be relatively inexpensive and make a fine necklace that goes with most fashion.

Some of the most expensive are the black opal. These are like the basic black of jewelry and can really complement what you are wearing very tastefully.

If you can try and pick an opal necklace in which the opal is held in pace with a claw rather than glued in. Glue has been known to deteriorate over time, especially with the perfumes, creams and chemicals in soaps that we put on our skin. They can have an adverse affect on the glue as well as the necklace.

The necklace could be made with 14 or 18 karat gold or platinum. Both are long lasting and hard wearing. Ensure the clasp is well made and not so hard to open or close that it breaks with the effort.

Ensure you get a certificate with the opal to verify its authenticity and value. This you will need for insurance purposes and also you might want to sell the necklace one day.

Maintaining your opal necklace is important too. A regular wash in warm soapy water and rinsed well will keep it clean of all the accumulated grime. Make sure it is dried well and stored when not in use in a separate container and not mixed with other jewelry such as diamonds which may scratch the opal.

With proper care and attention you can have a wonderful opal necklace that is long lasting and gives many years of pleasure.

All About Opals
What are Opals
Where do Opals Come From
Opal Information
Types of Opals
Is it a Real Opal?
Buy Opals
Sell Opals
White Opals
Black Opals
Boulder Opals
Opal Cutting
Opal Glossary

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