Aquamarine: Finding the gems that will give you rewards

Aquamarine is an iconic gem belonging to the same family that also features Green Emerald. Officially ranked as the birthstone for those born in March, Aquamarine gemstone has a glassy lustre and a sea-water hue. But are you aware that there are thousands of duplicate gemstone items that flood the market each year, and remain untraced. So how should one find and buy authentic Aquamarine.

Here’s what you should do.

Research about famous Aquamarine

Aquamarines are found as large stones that need cutting and polishing. Most of the naturally mined gems are either opaque or too dull to be used for profitable application. You must do a little research on the world famous Aquamarines. 

Dom Pedro:  Officially, Dom Pedro is the largest single piece cut-gem Aquamarine and falls in the category of rarest of rare natural items ever mined from the Earth’s crust. Named after the first two Brazilian emperors, Dom Pedro now stands as 14 inches in the shape of obelisk. It was cut from its 23.25 inches glory by gem artist Bernd Munsteiner.

The Hirsch: It is a 109.02 carat gemstone featuring an emerald-cut. It was one of the first non-treated gemstone to be exhibited all over the world. It was set in 18k gold bracket and diamonds by French Emperor Louis XV. 

The Schlumberger Bow: Currently ownedby the Field Museumof Natural History- Chicago, “The Schlumberger Bow” is set in platinum and gold pin along with diamonds. It is a 148.5 carat aquamarine designed for Tiffany. It was first exhibited in the year 1893.

Roosevelt Aquamarine: Gifted to First Lady of USA, Mrs. Eleanor Roosevelt in 1935, the gemstone is one of the largest naturally extracted aquamarines to be ever mined. It weighs 1847 carat. It was cut from a 1.3 kilogram stone of which a single 835 carat aquamarine was gifted to the Maharaja of Kapurthala.

The leading suppliers of aquamarine gemstone beads are Australia, China, India, Kenya, Madagascar, Mozambique, Namibia, Nigeria, Pakistan, Zambia and Zimbabwe. Radiant gems still come from Santa Maria mines in Brazil. So it is not all about the volume, but also about the position Brazil commands in Aquamarine gem market.

How to identify the originality

# Aquamarine Colour

Aquamarine can exhibit multiple shades of blue, variedly or consistently. It all depends on the amount of chromium and iron ions in the crystal lattice. The popular shades are light blue, deep blue,blue-green and green-blue. The cost of aquamarines is decided on the basis of the shade saturation and consistency. 

# Aquamarine Clarity/Lustre

Deep blue shades are costlier, only if they have a lustrous, crystal clear appearance. Some gems however can have rods running parallel seen like veins and inclusions. Aquamarine can show multiple optical characteristics like chatoyancy and asterism. 

# Aquamarine Cut and Shape

Aquamarine gems are cut in cabochon, but faceted cuts also hold significant place in collections. They are perfect for emerald cuts and square cuts. Emerald step-cut and Fancy Cuts are hard to manage, but they are popular among aristocrats as they were before World War II.

Opalescence: The Glorified History of Milky Stones

Searching for real opals? You should be familiar with the characteristic optical features that a natural, untreated opal exhibits. To check the authenticity of the opal, get it under a Turbidity meter. All opals exhibit an optical phenomenon derived from their own primary name- opalescence. It is defined as the milky and turbid appearance in opal. 

Opals: The Magic of Milky White

Often referred to as the stone from the Cosmos, opal is a Sanskrit word- Uppal meaning “precious milky stone”. It is a gemstone largely constituted of hydrated silicon di oxide. It is an amorphous stone and is extracted largely from the Southern Hemisphere. In fact, it is actually the National Gemstone of Australia.

The various forms of opal are:

1. Precious Opal

2. Fire Opal

3. Potch Opal

4. Girasol Opal

5. Blue Opal Gemstone, also called Peruvian opal

Opals actually exhibit both Play of Colour as well as Opalescence. 

How opalescence occurs in the gemstone?

Opalescence is confined largely to the blue spectrum during reflection of short wavelength light rays. It is because of this phenomenon that a gemstone appears turbid with a shiny blue surface. Another reason, it appears blue is due to the significantly high traces of water, which could be as much as 21% of the silica crystal volume. 

The spaces where water is present hinder the passage of light, making the gemstone look milky. Through these spaces, no diffraction occurs. The internal scattering around the water traces render the opal its characteristic opalescence.

Opals that made History

Opalescence can occur along with white, colourless, yellow, red, grey, black and fiery shades of red and blue as well. Diffraction causes flashes of Play of Colour. Intensity of opalescence decides the brilliance and clarity of the gemstone, and hence commands the price. The red opal beads as well as blue opal beads are extensively used in jewellery. 

Opals in flat cabochon glorify the opalescence in the most beautiful way. The most popular opal gemstones in the history of mankind are:

Sun God Opal:

A 16th century gemstone, carved from mines in Mexico. It is a 35 carat Aztec-era stone with a singular quality. It is a dazzling item showcasing opalescence and play of colours brilliantly.

Dark Jubilee Opal:

A thrilling example of Australian opal deposits, this 314.8 carat gemstone was mined from Coober Pedy. 

The Olympic Australis

Named after the Olympic Games in Melbourne, this is one of the purest mega-carat gemstone ever mined. Valued at $2,500,000 (Australian Dollars), it is a massive 17,000 carat opal exhibited all over the world.

The Butterfly Stone

Also named as the Red Admiral, it is a unique gemstone exhibiting opalescence at only certain angles. It resembles the red English butterflies and hence the name.

Empress of Australia

Rightly named, this gemstone was mined in 1915. It is referred to as ‘Kaleidoscope Queen’ and ‘Tartan Queen’. It weighed 500 carats in its initial days of glory.

Other prominent opals owned by museums and individual collectors are Pride of Australia, The Flame Queen, The Black Prince and Halley’s Comet.

 

A look into Heat Treatments of Rubies & Sapphire Gemstone

Rubies and sapphire gemstone available in the market are available in two forms. One category would be heat treated with additives, and another would be those without additives. It is obvious that though heat treatment is done to improve the colour of the gemstones, adding extraneous stuff to the crystal structure actually means that there has been physical distortion with the original gemstone. In short, gemstone that has been heat treated with additives is what you should stay away from.

Let us review how heat treatments with and without additives work, and why they are important in gem studies.

Heat Treatments without additives

Natural gemstones command higher price than those manufactured artificially. Natural stones may not be perfect in terms of their brilliance and crystalline structure, but their origin is all that matters. Gems created in labs have lower value primarily because they may not give the same healing benefits that they are known for. 

Heat treated rubies beads and sapphires are common, and they are respected for their consistency and suitability in different applications. They are heated under specific temperatures, glazed in condition that is free from impurities of any kind. Depending on the amount of oxides and the colour-bearing properties, rubies and sapphires exhibit the same beauty as their natural counterparts.

It is important to note that sapphires and rubies are heat treated using different agents. Heat treatment for sapphire gems is carried out in reducing process, while rubies are heat treated in an oxidizing environment. 

Heat Treatment with additives

The heat treatment process using additives is not illegal, but it affects the commercial viability of a gemstone. All gems have to be necessarily subjected to inspection by leading gem quality testing labs, and this is where additives are named.

The most popular gemstone treatment processes using additives for rubies and sapphire are:

Lead Filling

Also called fracture filling, this process is utilised to cover up the fissures and cracks. Rubies and sapphires with dull and rough appearance are infused with lead to produce high refractive indices. It can be used for opaque gems as well, which after lead filling result in brilliant transparent or translucent/ milky stones. 

Cheap rubies are available in the market, and they are more often than not, lead filled. Moreover, this additive process is actually reversible. Lead filling for gemstone has been rendered as hazardous, as lead is a carcinogen.

Recrystallization

In order to enhance the transparency and improve the refractive index, rubies and sapphires are made to undergo recrystallization. The first known synthetic ruby was actually produced using this process. Geneva Ruby in 1886 made headlines, but it turned out to be a reconstructed gem. Same process is used to produce emeralds. 

Beryllium Treatment 

An accidental discovery led to the commercialization of this process. Between 2000 and 2006, the market was full of richly coloured padparadscha sapphires. Lab testing proved that they were actually orange sapphires, diffused with beryllium ions. Even in natural stones, sapphires have been found to contain significant amount of beryllium impurities. 

Is it safe to wear irradiated Gemstones

It is true that even the most naturally obtained gemstones have to be exposed to some kind of radiation to make them look super cool. This process is called Irradiation and it is done by bombarding a stream of gamma rays at the crystal structure of the gemstone. It indeed makes the gems radioactive. Let us find out if the irradiated gemstones are anyway harmful to the consumers.

Which stones are irradiated?

Topaz is the most commonly irradiated gemstone. Blue topaz gemstone is one of the rarest gems, and is often manufactured synthetically. Nearly 28 million carats (which is roughly 6000 kilograms) of topaz are irradiated each year, globally. USA leads the source, followed by Germany, Poland and Thailand.

Other gemstones usually found in their irradiated states are yellow, blue, green and pink diamond gemstone. Quartz and amethyst beads are also exposed to radiation at some point of time in their life cycle. Goshenite, golden beryl and Heliodor are popular beryls available exclusively in irradiated states. Black pearls extracted after 1970, are either dyed or are irradiated to look stunning. 

So with so many precious gemstones exposed to radiation, it is obvious that consumers need to know to what extent they are susceptible to any hazard.

Is there any way gemstones are regulated in the market?

Yes. All irradiated gemstones have to be necessarily given a certificate from the regulating agencies in the respective countries. All gem producing and gem treatment nations have strict regulations to monitor the radioactivity levels in the irradiated gemstones, whether natural or artificial.

Here are some precious and semi-precious gemstones that have been ranked among radioactive items. 

 

  • Adularia 
  • Afghanite
  • Ajoite
  • Amazonite
  • Betafite
  • Boleite
  • Charoite
  • Eudialyte
  • Francevillite
  • Londonite
  • Polycrase
  • Sugilite
  • Thorite
  • Titanite

 

Despite their radioactive state, they are deemed safe for use on a daily basis.

Who testifies for irradiated gemstones in the market?

Irradiation is a very commercial process for manufacturing gemstones. The finished items have to be approved by Federal Trade Commission. Other prominent professional organizations are American Gem Trade Association, The World Jewellery Confederation and International Coloured Gemstone Association.

How to tell ifthe gemstone is irradiated?

A gemstone seller can’t sell irradiated items without necessary certification. One of the most recognised certification comes from United States Nuclear Regulatory Commission. Physically, it is very difficult for even the experts to tell whether the gem has been irradiated naturally, or in a reactor or in an accelerator. The certificate, followed by a testing with survey meter is the only way any lay person can adjudge the gemstones as irradiated or not.

Are they safe for daily wear?

Yes. The irradiated gemstones belong to the family of birthstones, and the customer is required to wear it daily for effective healing and metaphysical benefits. Irradiated gemstones don’t radiate back. The effect of irradiation is exhibited through the change in colour due to the distortion in the crystal structure. The change in colour is permanent and so is the non-radioactive state of the gemstones.

Hence, irradiated gemstones are absolutely hazard-free.

 

A look at Prominent Diamond Cuts since 13th Century

Going back to the 12th century, we will find the first instances of how diamond cutting became a trade of respectable position in the society. As royal families and noblemen began to showcase their pomp and glory through silk and gemstones, diamond slowly began to raise its head as one of the most precious items of collection in the treasury. The first diamonds were cut in manner that resembles the modern Point Cut. We are not talking about the trend in the year 1970, but in 1287. 

Here are some truly antiquated diamond cuts that still retain their place in modern day gem cutting trends.

Natural Points

Diamonds that crystallised in octahedral and do-decahedral crystal lattices are left uncut. These are natural crystals and have remained so for millennia. Before America and Australia were discovered and conquered, the only source of diamonds was the Indian sub-continent. A Point Cut diamond is actually a misnomer as there are no tools involved in the machining. 

Pyramidal Point Cut

Grinding became a regular gem cutting and polishing technique, especially after 15th century. Big diamonds were smoothened and polished without taking away their size. Out of multiple girdle profiles, a lapidary artist would choose the one with the largest contour in diamonds. Diamonds have always carried the charm of bestowing magical and healing effects on the person wearing them. Keeping them untouched and natural was no longer a fashionable trend. Hence, slight polishing using Pyramidal Point Cuts made at shallow planes compared to natural points became more popular. 

The Burgundian Point Cut

Burgundian Point Cut is preferred for diamonds with dodecahedral crystals structure. This crystal lattice has many irregularities and requires intensive polishing. The dodecahedron crystal is aligned in a way that the four faces seem as if rising upwards. 

Table Cuts

A remarkable refreshing cutting pattern, diamonds were first cut in Table Cut using diamond dust itself! The first Table Cut diamond was shaped like alphabet “M”. It was probably the first engagement ring ever gifted. Not to forget, before Rose Cut diamond became the symbol of love and romance, Table Cuts were the fashionable items.

Old Mine Cushion Cuts

Europeans dug out new sources of diamond gemstone. Amazon and Sahara became the diamond potboilers for traders. The new cutting models for vibrant diamonds beads meant embracing an indigenous gem shaping technique. Old Mine Cushion Cut took birth in the 18th century bearing an uncanny resemblance to what we know as Modern Brilliant Cut. They gave birth to the aristocratic cuts like marquise cut/navette cut.

Old Mine Cushion Cut was produced using bruting machine powered by steam, and later motors. English Round Cuts were born from the improvements in diamond bruting machines, some of which produced 58 flawless facets in a single diamond gemstone!

Asscher Cut 

Named after the world renowned gem cutters, the Asscher Brothers of Holland (they cut the world’s largest diamond- Cullinan), this is very similar to what we call Square Emeralds bearing large facets, small table and an elongated crown.

The World of Diffusion Sapphire Gemstone

Sapphires can be artificially treated in labs in many ways. One of the most prolific technologies to produce these gemstones is lattice diffusion. So let us do a quick review on the lattice diffusion sapphires.

What is lattice diffusion after all?

Lattice diffusion is a commercial gemstone treatment process that involves use of heat and chemical agents to diffuse the ingredients into a gemstone so that it will change colours as per requirement. The best part of using this technology is that gemstones of any colour can be produced. Sapphire gemstone showcasing myriad colours like vibrant red, fiery purple, electrifying blue, silky yellow and pitch dark blacks are produced using diffusion through the crystal structure.

In some cases, sapphire beads are treated with lattice diffusion that can have shallow embeds of colours superficially exhibited on the surface. In others, the colours can penetrate deep into the very core. It all depends on the conditions and impurities already present in the crystal structure that interact with each other randomly during diffusion.

Is lattice diffusion for sapphire legal?

Heat treatment is a legal and accepted technique used on sapphires and rubies. Lattice diffusion however, require regulation from top gem laboratories and trade organizations as far as production and selling are concerned. Lattice diffusion, in no way, adds monetary value to the gemstone. It only improves the brilliance and clarity with a more consistent appearance. 

It is legal, and is very different from the process of dyeing and stabilizing. The molecules added to the crystal structure can’t be detected even under the most powerful microscope. Hence, a gemstone dealer has to necessarily produce a certificate labelling the stone with lattice diffusion.

Types of diffusion methods 

 

Apart from lattice diffusion, certain gemstones are also treated using Surface Diffusion and Pipe or Channel Diffusion.

Surface diffusion

It is the addition of natural colouring elements like iron, copper, titanium and chromium to the shallow surface of a gemstone during heat treatment. 

It is sued largely on corundum and silica-based gemstones after cutting is done.  

The colour penetration is usually less than 30%.

It is done at melting point of the element so that it diffuses evenly into the crystal up to a depth of 1 millimetre. 

Surface diffusion is done for blue sapphire beads and rubies. Colour obtained on a gemstone using the surface diffusion could be lost due to re-polishing, scratching or resetting.

Channel Diffusion

Also called as pipe diffusion, this heat treatment technique is applicable to feldspar and Labradorite gemstones. It is done using copper as the diffusing element. The diffusion occurs along the channels and can be easily detected under microscope. 

Identification of surface and channel diffusion sapphires is done by studying the bands and zones running parallel to the crystal facet.

Unlike the gemstones that are heat treated using chemical dyes and fillers, those produced using lattice diffusion are relatively sturdy and long lasting. They cost a little less than other varieties but exhibit the same brilliance and clarity. Moreover, they are easier to machine and cut.

 

How to identify the treated and untreated Sapphire gemstones

In gemstone market, it is very hard to find an untreated piece because of the lack of interest from the buyers. Untreated sapphire gemstone is often mistakenly referred to as natural. The treatment process has nothing to do with the origin of the gemstone in any way. Lapidary units create eloquent sapphire gemstones using elaborate treatments. 

Let us find the real differences between the two families. 

Untreated gemstone

The stone that has been developed from the ground and never cut or polished in any way in a lab is labelled as ‘natural’. When the natural stone is not subjected to any chemical or heat treatment, it qualifies as an untreated gemstone. 

Heat treatment, optical irradiation and chemical treatments are done on various gemstones to achieve brilliant colours, clarity and some times better refractive index. Sometimes, a treated natural gemstone is easier to cut and polish than the untreated ones due to better clarity and machining properties.

What happens in gemstone treatment process?

All stones available in the market are subjected to treatments in some form or the other. Heat treatment process changes the colour and clarity. It is during this process that additives and glue are added to fill cavities, fractures and cracks. 

How to identify a pure gemstone?

Gemstone buyers should know certain tell-tale signs to identify 100% pure and natural stones. Regardless of the tag, here are some of the signs you can check to verify the claim of authenticity.

1. Naked eye test 

A true natural stone will reflect light and exhibit lustre. There are many stones that have a dull, waxy and shiny surface. There are some with greasy and silky appearance. High quality stones will reveal rings, stepped granules, splinters and sometimes clear waves inside them. Any polarised chipping in the stone highlights its synthetic origin.

2. Hardness and clarity

Most gemstones have hardness close to diamond. They can’t be scratched or cracked easily. Artificial gemstones, bordering at being fake, are created in the lab and resemble glass. A gemstone from natural treated family will have pure clarity and no cracks. In case of fake artificially treated stones, you can clearly see speckles and minute cracks within the structure arising due to intense heat and pressure

3. Density 

Original stones even after heat treatment will retain their density. Synthetic stones that are subjected to heat treatment gain a few points and actual weigh heavier than the natural stones. This is how lapidary and stone collectors verify Blue sapphire gemstone.

4. Crystal layers

Most gemstones from the natural deposits have a parallel layer running inside the surface. This is what gives the stone its saturation and intensity. For warm coloured stones, look for brown tinge. Reject the stone if you see even the dullest shade of greyness.

The colouring dyes and reinforcing agents diffuse completely throughout the crystal structure uniformly. Some heat treatments produce dramatically altered gemstones that not only look brilliant but also compound the original hardness.

How to identify a genuineAquamarine gemstone

Aquamarine is blue green gemstone cut in variety of shapes. Cabochon, Fancy and Emerald step-cut are popular among the gem cutters, who cater to the demand of the art galleries and collectors from across the world. But are Aquamarines worth the attention they get in the gem market? 

Here is how you can find and authenticate a genuine Aquamarine and stay clear from disputes.

1. Heat treatment for colour enhancement 

Aquamarine gemstones are heat treated to enhance the colours and impress the consistency. Many untreated aquamarines are also available in the market, but they exhibit translucency and opacity to a certain degree. High quality Aquamarine gemstones are identified by their lighter shades, which means they may not have been heat treated. The stones heat treated to 450 degrees centigrade are often found to have darker shades, but may not be a high quality beryl.

Note: Aquamarines heated beyond a specific high temperature lead to irreversible discolouration. Thus the spectrum of authenticity is very small as far as gems heat treatment range is concerned.

2. Is an aquamarine only blue in colour? 

Aquamarines fall in the category of clear blue and clear green beryl family. The coloured Aquamarine and Chrysoberyl resemble very closely to each other. The colourless variety is called Goshenite, but is now tagged as colourless beryl.

3. Specific Gravity is higher than other stones 

Aquamarines are heavier than other gems. The stones extracted from Latin American mines have a specific gravity ranging between 2.66 and 2.80. The ones mined from Asia and African mines have higher density due to greater presence of alkali ions. 

Gems are immersed in liquids with higher density and the results are noted. Whether the gemstone floats or sinks into the liquid decides the authenticity of Aquamarine. 

4. Refractive indices 

Aquamarines beads have a refractive index ranging between 1.572 and 1.590. It exhibits a brilliant and unhindered impression when exposed to white light.The originality of the stone is established by placing it under Refractometer. Here are different optical phenomena observed in the real Aquamarine. 

Pleochroism

Aquamarines can exhibit colour dichroism owing to the presence of more than one colouring ions like chromium, iron and copper. The strength of the colour depends on the percentage of the ions. Birefringence can range between 0.005 and 0.008, which represents the saturation of the colour.

 

Iridescence 

Conchoidal fracture in Aquamarine can cause rainbow effect. It is caused due to diffraction combined with interference. 

The Cat’s Eye effect

Aquamarine exhibits chatoyancy due to the presence of rutile in the crystal structure. Rutile is composed of titanium dioxide and can be found in traces in gemstone families like quartz, beryl, chrysoberyl, charoite, tourmaline, feldspar, Labradorite, moonstone, apatite and tourmaline.

Asterism 

Asterism in Aquamarines is a rare phenomenon, but not an exception. Polished, untreated Aquamarines from Brazil show 4-ray star patterns sparingly.

There are different closely linked beryl gems that can be confused with Aquamarine. Study the colour and the crystal lattice under a microscope for further verification.

Exotic Purple Gems Come From Amethyst Treatment

A rousing gemstone in its purple brilliance, amethyst is one of the key items used in jewellery. Essentially quartz, amethyst gemstones is derived from Greek, which translates to “protected from intoxication”. Its natural colour ranges from light pink to deep overtones of purple, often resembling pigeon’s blood. 

In the market, finding a brilliant purple amethyst gemstone from natural deposits is almost impossible. Amethyst gemstones are produced abundantly from the mines of Brazil, to be precise, at Minas Gerais. A place in South Brazil that is revered for its rich paleontological importance, the mines produce largest deposits of the Sobriety Stone. 

In order to exaggerate the light shaded amethyst stones produced from mines elsewhere other than Brazil, the gems are treated synthetically. The colour and the properties attained after undergoing the treatments remain irreversible. 

Why is Amethyst Purple?

Amethyst is quartz with iron and aluminium impurities impregnated in the structure. Closest siblings to amethyst are Golden citrine and Ametrine.

Here are different amethyst treatments and the effect they have on their commercial value and pricing.

Heating

The finest quality of amethyst stones exhibits a strongly reddish purple to light pink with zero zoning on them. Gem dealers prefer to display only amethyst stones with saturated reddish purple with a bright radiance. Natural dark amethyst may look blackish when observed in dim lights.

This is where heat treatment is brought into the picture. Very dark amethyst gemstones are gased in high temperatures to lighten the shade. When done in controlled temperatures, gem manufacturers actually manage to produce light but more saturated shades. 

Heating is done at 400 degrees to produce astonishingly stable shades of royal purple. It causes tiny inclusions due to expansion of fractures already existing in the crystal structure. The process imparts a permanent colour that will last forever. All dramatic coloured amethysts have undergone heat treatment at some point of their life.

Irradiation

Sometimes when amethyst gems are not available in the market as per demand, the lapidary takes irradiation as a primary course to produce synthetic amethysts. Commonly, synthetic gemstones are made to resemble amethyst by bombarding Yellow Citrine with Gamma rays. The iron oxide particles in the crystal structure of yellow citrine re-oxidize to give it a natural looking purple shade. 

The advantages of using irradiation process to produce marketable amethyst gemstone beads are:

100% reversible process, if not subjected to heat treatment

Cheaper process if done for bulk orders

A large variety of stones can be used to produce amethyst under lab conditions 

Amethyst Treatment 

Amethyst is seldom subjected to heat treatment. The transformation of amethyst gemstones yield Vermarine or Prasiolite, as it is known more commonly in the market. Natural looking Brazilian amethysts turn to the green-coloured vermarine, at a temperature ranging between 800 to 1350 degrees. 

Treated amethyst is cut in rounds and ovals, and hardly in cabochon. Calibrated sizes of amethyst can be shaped in exotic patterns resembling hearts, trillions and shields. Ornamental carvings made of amethyst retain their shade and physical brilliance much longer.

The Story Behind the Irradiation of Gemstones

Different gemstones exhibit a varied reaction to different types of treatments. One of the most popularly used treatments to produce brilliant gemstone is the process of irradiation. Light blue topaz gemstone turns into dark brown after radiation. The same brown topaz gemstone is reversed to its original blue colour by exposing it to a controlled heat treatment under specific conditions of temperature, pressure and catalysts. 

What is irradiation?

Irradiation is just a miniature controlled nuclear attack on the gemstones. Imagine the crystal structure as the target, and a series of gamma ray bombs hit specific spots inside the gemstone. The bombardment of the gamma rays alters the colour of the gemstone significantly, without actually making little or no difference to other physical aspects like hardness or density.

Irradiation can lead to both addition and removal of certain ingredients in the structure leading to change in hue. There are certain colour centres within the crystal structure that give different shades when bombarded with gamma rays. That is why irradiation of gemstones is achieved not by trial and error, but using specific nuclear kits.

Does irradiation cause any kind of damage to the precious gemstone?

Basically, the process of irradiation is a great way to produce brilliant gemstones from rather disappointingly dull stones using no physical force. When the gamma rays hit the colour centres within the crystal structure, the cells are knocked out in a random motion. The systematic process of irradiation can produce brilliant colours which are permanently restored and made more attractive by exposing the stone to heat and pressure.

Is irradiation a permanent process?

The fact that gemstones irradiated using gamma rays are produced under intense temperature makes them a permanent item to wear. The colour is long sustaining and can possibly be reversed to its original shade by applying an equally high bounty of energy. It is certainly an irreversible colour transformation process as far as irradiated gemstones like topaz are concerned.

Is irradiation a costly affair?

Of course it is! Otherwise, all the blue topaz available in the market would look like brown speckled stones with absolutely no commercial viability. Almost 95 percent of the blue topaz are irradiated and treated with heat before they get their signature shade. 

Irradiation is done using highly powerful nuclear bombardment machines that cost millions. Only organizations having certificate to operate a nuclear machine can use it. Moreover, it requires skilled gemologists and operators who understand both aspects of gemstone properties and nuclear physics.

Thus, the cost of irradiation of gemstone is a pricey affair. But it ensures that the end consumers get only high quality gemstone produced from natural extracts and polished by skilled professionals.

Are there certificates to tag irradiated stones?

Yes, there are different certifications offered across all continents to ensure gem quality. It also ensures that none of the gemstones have turned radioactive. The major certifying units are GIA, AGS and other renowned gemstone research labs.