Opal is a highly valuable gemstone, and it’s never a good day when you accidentally acquire a fake because you weren’t aware of the difference between the two. This particular kind of silica mineral is an amorphous and hydrated variety of the mineral silica, and it contains significant amounts of water.
It is technically classified as a mineraloid and may be discovered in rock fissures, which can be found in abundance. Opal may occur in various rocks, including basalt, limonite, rhyolite, and marl, to name a few.
Australian opal is the world’s most abundant source of opal, and it also happens to be the country’s official national gemstone. The presence of water in opal distinguishes it from all other gemstones that are commonly gathered, and this causes it to diffract light more than the others. Genuine opal is available in various hues, including white, orange, yellow, brown, magenta.
Table of Contents
How Can I Tell if Opal Is Genuine?
In contrast to other gemstones, Opal is not a kind of mineral. Opal is a mineraloid, which means it is made of minerals. Essentially, it indicates that the mineral opal lacks a crystal structure. It is a hydrated and amorphous form of the mineral silica. The gem of Opal is comprised of small spheres that are organized in a grid-like structure.
The water content of opals can reach up to 20% of their total weight. For this reason, it is recommended to store opal away from direct sunshine. Opal may be found in rock fractures. Basalt, limonite, and rhyolites are just a few rocks that may produce opal when the conditions are right.
Real opal has a spectacular dance of colors, or luminosity, equally distributed rather than in an erratic pattern. It may be found in a range of hues, ranging from white through the whole spectrum of the rainbow to black. It does not have any dark soot patches or a columnar structure.
Because of light diffraction, precious opal exhibits a play of colors, often known as opalescence. When light waves move between silica particles, they diffract or bend, a technical term.
Because of their bending, they disintegrate into hues from the rainbow or spectral colors. We may see the consequence of this procedure as a play of colors or iridescence due to this process.
The hue of the spheres is determined by the sizes the spheres. To generate violet, little spheres with a diameter of around 0.1 microns (one ten-millionth of a millimeter) are used. Red is produced by spheres that are around 0.2 microns in size. The sizes produce the remaining rainbow hues in between.
Australia is the world’s largest source of opals (suppliers account for 80 to 95 percent of global opal production), and opal is the continent’s national gemstone.
Spotting Real Opal vs Fake Opal
There are various methods for determining whether or not the gemstone you have is genuine.
1. Examine the Opal’s Reverse Side:
Do you observe tiny layers that appear to have been glued on the water’s surface? This is yet another instance of artificial fusion, and sure, it is possible to have a doublet or triplet. Unlike other gemstones, pure precious opal does not attach to other gemstones.
Checking the back of the specimen for signs of modification or artificial opal construction is another indication that you may be handling a modified or fabricated opal.
The backing of synthetic or modified opal is often comprised of smooth plastic. Real opal can’t have a perfectly flat and smooth back because of the way it is formed naturally.
A very small amount of valuable opal is typically bonded to a sample of its host rock (also known as the brown boulder) or to other supporting material such as glass or vitrolite.
The existence of any extra material that has been bonded to the primary opal body suggests that the producer has made significant modifications to the piece.
2. Visual Test:
The water fog test is another visual test that is surprisingly accurate in its results. Immerse the opal in water for some time, allowing the piece to absorb part of the water.
Some water may infiltrate between adhesion layers if you hold a triplet or doublet in your hands. When you hold the item up for examination in bright natural light, you will notice moisture seepage between both sheets.
3. Examine the Opal’s Surface to Ensure It’s Not Cracked:
Even though it is a mineraloid, genuine valuable opal does not look glassy. Another coating was presumably applied to the opal after it was polished to give it the appearance of being polished. This was done for protection and beauty reasons.
The capping of multilayer opal structures can be made out of several materials. Some producers cover expensive opal with plastic, while others use well-polished glass to protect the gem.
Even if the glass is well polished, it is still glass and will attach to the gemstone. You are likely holding a triplet if you view the opal from the side and can easily see right through the first layer of the stone.
On the market nowadays, you may also get synthetic opals. This type of mineraloid can be difficult to distinguish from the actual or natural mineraloid since it is intended to resemble the found natural mineraloid. Untrained gemologists and jewelers will be able to determine if the specimen is genuine precious opal or artificial opal.
4. Check to See if the Opal Is Lined or Has a White or Black Background:
Check if the opal is lined or has a white or black background. If it does, then the mix of minerals is artificial, and depending on the number of hues you have, you may be carrying a doublet or a triplet of the minerals in your possession. It is possible to obtain genuine opal in doublet or triplet form; however, this is not always the case.
When opal is bonded to form a double or triple opal, other minerals are utilized to finish the structure, and the adhesion holds the two or three pieces together. Plastic backings are also used in these structures by laboratories and businesses.
How to Identify Real Opal?
Opal is a solid stone in its natural state. This indicates that it has not been glued or fused from several components.
Real opal has a uniformly distributed play of color across the whole body and appears the same from both the front and side views.
When viewed from the side, real opal does not have a columnar structure.
Real opal does not have the lizard skin or snakeskin look, which indicates that the stone does not have a regularly ordered pattern of color flashes on its surface.
Opal that has not been smoked or treated with sugar should not contain any soot spots, which would indicate that the stone has been smoked or treated with sugar.
If Synthetic Opal Is Referred Regarded as “False Opal,” Is This Correct?
Though it should be emphasized that synthetic stones will not have the same value as mined genuine opal since they are manufactured in a laboratory, this is not the case in this case.
Lab-grown gemstones are regarded as superior alternatives to naturally existing gemstones, and they are also far less expensive than naturally occurring ones. Even if you buy different jewels, such as diamonds, the same rules apply.
Lab-grown diamonds are far less expensive than natural diamonds found deep under the Earth’s surface. They are chemically similar to the diamonds found naturally far beneath the Earth’s surface.
Another thing to keep concerning lab-grown opals is that producers may occasionally include other materials in their production. As a result, when this occurs, the lab-grown diamond is no longer chemically equivalent to the mined valuable opal, according to chemical theory.
The enhanced porosity of synthetic opals distinguishes them from naturally occurring opals, which is the most distinguishing characteristic. The density of lab-grown gems is also far lower than that of natural silica, resulting in a finished product lighter and more porous than natural silica.
Lab-grown opals will also exhibit extremely consistent color structures when examined under a lens. Real gems will contain inherent imperfections within their mineraloid structures because they were generated by temperature and pressure fluxes during their formation. If you flash a UV light on a synthetic opal, it will also become completely opaque.
How to Tell Whether an Opal Is Fake?
Before detecting fake opal, let’s first distinguish between the most frequent forms of opal forgeries. Fake opal manufactured of glass may be distinguished by the presence of small films inside and circular bubbles and swirls.
Fake opals constructed of plastics and resins will have a highly uniform opalescence, which customers frequently demand. Fake opals that have been assembled are composed of two or three layers apparent from the side perspective.
Fake Opals are a classic:
The following materials are commonly used to create imitation opals:
Artificial grass is an ancient gem imitation that is still commonly used today. Today’s technology enables the manufacture of glass in virtually any hue.
As a result, it is the most often used counterfeit of many precious stones. Opal is no exception to this rule. The glass substance known as “Slocum stone” can be used to create an opal-like appearance.
Slocum stone is a kind of silicate glass that contains small transparent flakes of iridescent film that form an opal-like dance of color when illuminated.
Opalescent glass is the other common opal simulant that may be found. It is a type of artificial grass with a sheen-like gloss.
Resins and Plastics:
The resins and plastics that make up the second faux opal category are illustrated. Opalite is a brand name that is sometimes used to refer to an artificial material with an opalescence effect. Because of the high resin concentration of these opals, the physical characteristics of the substance are altered.
Opalite has lower specific gravity and refractive index than natural opal, which is more transparent. A heated metal needle may also distinguish between plastics and resins. The smell of burnt plastic is emitted when the needle is touched.
How Can You Tell If It’s a Fake Opal?
Color flashes grouped in a repeating pattern can distinguish real opal from fake. Swirls or bubbles within a fake opal manufactured of glass and conchoidal fracture can be used to identify the fake opal. When seen from the side, fake opals made of various materials can be distinguished from genuine opals. The texture of synthetic opals is similar to that of lizard skin.
The fake opal is far too reflective. It exhibits a kaleidoscope of color flashes grouped in a repetitive pattern.
In the inside of fake opals made of glass, you will find swirls and circular bubbles. In addition, they will suffer from a conchoidal fracture.
Fake opals are made out of several separate plates bonded together.
When viewed from the side, the fake opals have a columnar structure.
When the hot metal needle hits the fake opals made of plastic, they emit an odor similar to burnt plastic.
Frequently Asked Questions:
What are false opals?
Synthetic opal has a lizard skin look or color flashes that are organized. From the side, synthetic opal seems columnar. Artificial opal is porous, lighter density, and not glow under UV light.
How to recognize an opal?
Hold your stone up to the light and examine it with a lens or jeweler’s loupe. If the gem has little bubbles on the surface, it is likely a glass copy.
How do you tell a raw opal?
The body tone and clarity of natural opal influence its variation. Body Tone – The body hues of light, dark, and black opal span from colorless white to black. The translucent opal is an opaque opal with a translucent body.
Now that you know how to identify if an opal is genuine, you can put your knowledge to use to choose the greatest opal to add to your collection. Opals are not only gorgeous and one-of-a-kind, but they are also incredibly precious due to their rarity and scarcity.
Finding a valuable opal can be difficult, but it can also be rewarding for those who know what to look for. If you come upon a valuable opal, you might want to try utilizing it to make a unique piece of jewelry.