Ruby is one of the most misunderstood gemstones of the past few decades. At least to the majority of the population. Most believe ruby is some cheap red gemstone found in mainstream jewellery shops of a shopping mall. And is no fault of theirs. Rubies used in 'mainstream' jewellery shops are usually synthetic (lab-created) or lead glass filled rubies because that what's commonly available at a low cost. Marketed as a cheap and readily available red stones; that's the general misconception of ruby. The actual natural gem is so rare only those who understands its beauty, origin and history can truly appreciate it as wonder of nature. In fact, rubies are more valuable than diamonds when it comes to price per carat because fine quality rubies never come in enormous sizes. The finest of rubies comes from Burma (Myanmar). It's the only source in world for chromium rich rubies, African rubies are iron rich and doesn't not compare in quality. Browse our collection of Burmese Rubies or learn more about the qualities of rubies in the Ruby Buying Guide below.
Ruby Buying Guide
Colour is a very important factor when buying a natural ruby. It can have a big impact on the pricing of a ruby. The most desirable colour being Pigeon Blood, a vivid red colour without any brown, purple or orange overtones. That said Ruby has a wide range of colours starting from the pinkish-red colour to deep garnet like dark red. Many sellers will try to push their pink sapphires as rubies to get that extra premium that comes with the name, ruby.
Saturation and Tone
The difference in saturation and tone can cause a big difference in price. As an example, a ruby that is well saturated in colour but has a very dark tone like that of a garnet has a much lesser value than that of a medium tone. As the colour become less saturated, red becomes pinkish red colour and also has a different value to the more saturated reds. Saturation refers to the amount of colour that’s in a gemstone while the tone indicates the lightness(Light, Medium, Deep) of a stone.
Cause of Colour
Ruby is an allochromatic gemstone which means that the colour in it is caused by trace impurities. Ruby is the only colour in the corundum family that has its own variety name. All other colours besides red are called sapphires. Ruby in its pure chemical composition is colourless (aka colourless or white sapphire). The main cause of colour in rubies is the element Chromium. High Chromium content gives the ruby an high intensity vivid red colour.
Almost all natural rubies will have some kind of inclusions. It's extremely unlikely that a natural ruby will be internally flawless. So, forget about getting a perfect ruby. Even eye clean rubies are very rare. Most rubies will be included to some extent. One just cannot expect rubies to have the same level of clarity as a tourmaline, spinel, aquamarine or quartz. When one is available in an exceptional eye clean quality be prepared to pay an extra premium especially if it's unheated.
Natural Burmese Rubies are more expensive than diamonds in price per carat. That's because rubies don't come in enormous sizes like diamond at least not in facet quality. Sizes above 1.5ct starting to become very rare. Only specialised high-end gems dealers will carry natural rubies above 2ct.
Do not expect any sorts of fancy cuts. Rubies are so rare they are only cut into shapes that the rough material will permit. Anything else would be a waste of rare, expensive material. Cut is an important factor in judging the quality of a ruby. Almost all rubies that comes out of Burma will be cut to retain maximum weight because they are sold on a price per carat basis. A high quality Burmese ruby is usually double the price of a similar quality African ruby, if not more.
Origin is an important factor when it comes to fine quality rubies. Up until the recent decades Burma (Myanmar) supplied most of the world's ruby demand. Now, new deposits have been found in places like Mozambique and Madagascar that supplies the majority of the market. Even than, Burmese rubies are till regarded as the finest quality of rubies in the world because of their chemical composition. The amount of Chromium contained within a Burmese ruby is unmatched to any other ruby bearing localities in the world.
Ruby is one of the most commonly treated gemstone because of its high value. To begin to understand treatments, one must understand why it is done in the first place. It all boils down to supply and demand. Natural ruby is considered very rare being only found in a few localities around the world. With its alluring intense red colours, the demand for them are higher than what the mines can supply. This is where the treatments are used to fill in the supply gap. A treatment will change the appearance of a ruby by enhancing the colour or clarity or both. This can turn a lower quality ruby into something of higher quality in appearance. Some methods are acceptable, while some are treated to a point that they are no longer consider rubies. Below are a list of known treatments used on rubies.
Heat Treatment of Rubies (Heat)
Also known as general heat or traditional heat in the trade. Not to be confused with other types of treatment that also involves the use of heat. The process does not add any foreign substances to the ruby. This type of treatment is generally acceptable by many as standard industry practice. The process can improve both the colour and clarity of a ruby. Most of the natural rubies in the market has been treated in this way. The treatment is permanent and stable.
Heat Treatment with Flux (Flux)
The treatment is similar to the normal heat treatment but the rubies are heated together with a type of flux like borax. During the treatment process, the flux enters into the fractures and fissures of ruby. Once cooled (healed), the flux healed fractures are less apparent to the naked eye and thus enhancing the overall clarity.
Beryllium Diffusion of Rubies (Be)
Sometimes known as lattice diffusion, it's different from the traditional surface diffusion on blue sapphires. Beryllium diffusion can penetrate deep into the crystal lattice to form colour zoning within the ruby which will result in an enhancement of colour. The treatment is more common with sapphires but can also be performed on rubies. The treatment is permanent and stable.
Lead Glass Filling of Rubies (Pb)
Rubies that have been treated in this way are lowest of all qualities although they have have a high quality appearance. Most large rubies at a low price are of this treated type. Very low quality natural rubies of near transparent to opaque clarity are heated with lead glass. The process allows glass to flow into the fractures and fissures of the low quality ruby, hiding them. The treatment is not permanent and unstable. Lead glass filled rubies have many durability issues.
Surface Filling of Rubies
As the title suggests, the treatment is done to the surface of a ruby. Natural ruby rough can come with many flaws including cavities. After the stone is cut, sometimes, these cavities can remain on the surface of the ruby gemstone. Rather than grinding down the holes (which will result in a smaller gemstone overall), they are filled with glass like silicon fillers. This is different to a glass filled ruby.
This is a term commonly used in the trade that buyers have to be aware of. An Untreated Ruby doesn't necessarily mean the ruby is free from any treatments. It should but the word's definition has been lost in translation through sellers whose main language is not English. Untreated rubies usually just means they not glass fracture filled but are heat treated.
Diffusion Treated Star Rubies
The star seen on the surface of a star ruby can be artificially induced by a surface diffusion treatment. These star are usually very sharp and well defined similar to that of a high quality natural star ruby.
Before and After Heat Treatment
On the left are sapphire roughs before heat treatment. On the right, after heat treatment the colour has been enhanced greatly. This is one of the reasons why unheated rubies have a higher premium than heated ones. They are already perfect naturally.
Ruby Treatment Terms
There are many different terms used to describe the types of treatments applied on rubies. Many sellers will introduce new terms to confuse a gullible buyer. Below is a list of known commonly used names used in the industry.
|Trade Term||Possible Treatments|
|Unheated Ruby||No Treatments|
|Untreated Ruby||Heat, No Treatments|
|Heated Ruby||Heat, Be, Pb, Flux|
|Treated Ruby||Pb, Be, Flux, Heat|
|Diffusion Treated Ruby||Be|
|Fracture Filled Ruby||Pb|
|Lead Glass Filled Ruby||Pb|
|Clarity Enhanced Ruby||Pb|
|Flux Healed Ruby||Flux|
Ruby Price Guide
The price of a ruby is dependant on all the factors above: Colour, Calrity,Cut, Weight, Treatment and Origin. It’s important to consider all the factor on each stone to determine its price. Note that this is a rough price guide and does not take into account every possible factors that affects the value of rubies. Prices are is based on faceted rubies of top colour, eye clean clarity with average to excellent cut. Current as of 2019.
|Colour||Carat||Price Per Carat (USD)|
|Pigeon Blood - Burma Unheated||1.0 - 2.0||$15,000 - $25,000|
|-||2.0 - 3.0||$25,000 - $50,000|
|Red - Burma Unheated||1.0 - 2.0||$8000 - $10,000|
|-||2.0 - 3.0||$10,000 - $25,000|
|Vivid Red - Mozambique Unheated||1.0 - 2.0||$7000 - $15,000|
|Pinkish Red - Burma Unheated||1.0 - 2.0||$3000 - $12,000|
How to Identify Red Spinel From Ruby
Separating Ruby from a ruby is an easy task by use of a polariscope or a dichroscope. Spinels coming from the cubic crystal system is optically isotropic. Ruby from the corundum family forms in the trigonal crystal system and has a single optic axis in an otherwise doubling refracting gem material. By examining the stones on a polariscope, one can easily differentiate an singly refractive stone (spinel) from a doubly refractive gemstone (ruby). Another quick method to separate the two is to look at the gems through a dichrscope; a red spinel would show red/red reaction whereas the ruby would show a purplish red/pinkish red reaction. These testes is only valid when the identity of each gemstone is already known and it just a matter of separating the two materials. As an example, a red garnet (in place of the spinel) will show the same results in this test because it also belongs to the cubic crystal system.
How to Identify Ruby From Red Garnet
Although a fine quality ruby is visually distinct from a red garnet, some rubies with darker tones may resemble a red garnet. Given the similarity in appearance though, price of the two gemstones are not the same; red garnets are much less valuable. Therefore, it is important to distinguish between the two. Lucky for us, the task is simple using a LWUV (Long Wave Ultra Violet) torch. Rubies being coloured by chromium will illuminate strong to moderate red while garnets will be inert.
How to Identify Ruby From Red Glass
Glass is a common imitation for many gemstones and a red coloured glass can certainly fool an untrained eye to being a red spinel. Identification between the two should be straight forward just by using a 10x loupe. On the external surfaces on the gemstones, look for abraded facet edges, chips and scratches. Features like these are commonly found on glass because it's such a soft material. Inside the gemstones, look out for natural and synthetic features. Synthetic glass has would have features such as colour swirls and gas bubbles. Natural spinels may have crystal inclusions, heal fractures and multi-phased inclusions. If there are no such features visible and both stones are flawless, it's also possible to use a spectroscope to observe the difference in spectrum. Red spinel has a clear diagnostic spectrum.
How to identify Lead Glass Filled Rubies
The key to separating lead glass filled rubies from natural rubies is in the inclusions. With the help of a 10x loupe, one can examine the rubies for unnatural inclusions like gas bubbles. Gas bubbles are never present in a natural gemstone with a few exceptions but never in rubies as a single phase inclusion. Somtimes this can be a challenge because the bubbles can be minute or hidden with other natural inclusions. It's best left for a trained gemmologist to identify these rubies.
How to identify Synthetic Rubies
Separating a natural from an synthetic is best left to a professional gemmologist. Some exceptional natural rubies may resemble the appearance of a synthetic gemstone because they are too perfect. Synthetic rubies created by the Verneuil flame fusion method are easily identifiable with the aid of a microscope. Flux grown synthetic rubies are harder to distinguish from the natural. Identification of these flux grown material may require advance instrumentation.
A number of gemological testes can be used to easily separate ruby from other red gemstones.
Care and Handling
Rubies are 9 on Moh's hardness scale second only to Diamond. They are a very durable gemstone ideal for all types of jewellery including engagement rings and jewellery for everyday wear. The mineral does not show any cleaving properties, although it should still be handled with care to avoid chips through impact just like any other gemstones. Lead glass filled rubies are less durable and needs special attention when handling. Below is a list of special handling instructions for jewellers.
Ruby is considered safe around a jeweller's torch. Avoid direct flame onto the gemstone. Higher level of caution needs to be taken when handling included rubies especially with surface reaching fractures. Lead glass filled rubies cannot go anywhere near the jeweller's torch.
Rubies are all-round chemically resistant. Safe to be placed in a jeweller's pickle except for lead glass filled rubies and rubies with surface in-fillings.
Ultrasonic is generally fine to use on rubies. Care must be taken to not prolong the use of ultrasonic when cleaning included Rubies. Prolonged cleaning in the ultrasonic may cause existing fractures to expand. Extra caution needed for lead glass filled rubies.
Ruby is safe with a steam cleaner.
Sources of Ruby
500 AD - Current
Burmese Rubies are perhaps the most well known in the world for their colour and quality. There are three different localities where rubies are found in Burma: Mong Hsu, Mogok and Namya. Rubies mined from Burma are known to have the highest Chromium content compared to anywhere else in the world. The resultant ruby is strongly florescent under UV rays. Mining operations in Mogok has been recorded in history to date back to the 6th century AD. The area has been under strict control by the different rulers of the land over time up until now. Through 1889-1931, when Burma was under the British colony, mining in Mogok was conducted by a British firm Burma Ruby Mines Ltd. Their studies showed that the highest yielding deposits would be underneath Mogok which lead to the relocation of the entire village. In 1929, prolonged monsoon rain storms flooded the mine which formed the lake in the middle of Mogok as we see it today.
Another important source(but not well known) for Burmese rubies is located in a remote mountainous area call Namya or Nanya (aka Nanyazeik) in Kachin state, upper Burma. Mining activities only began in the late 90s and production is kept at an minimal because of the difficult terrain.
Open pit mine in Mansin, Mogok where miner use high pressure hoses to wash down gem bearing mountain side.
334 BC - Current
Sri Lanka gem gravels have produced a very small portion the ruby supplies in the world. Rubies found here are lightly saturated in colour and tends to be more on the pinkish-red side of the spectrum. Though the source is there, not many rubies has been found but those that have been found are analysed to have near equal levels of Chromium as Burma rubies.
Afghanistan / Tajikistan
2000s - Current
Rubies from this region are also comparable to that from Burma but very little facet quality rubies are found and not enough to warrant as an important source.
2000s - Current
Rubies from Madagascar are a recent discovery, found only in the 2000s. There are two main deposit sites: Vatomandry and Didy.
1980s - Current
Vietnam has produce some rubies that can be matched with the Burmese ruby quality from the Luc Yen region , north of Hanoi. Only very little qualities have been found even for the lower cabochon grades.
1990s - Current
Small quantities of high quality rubies have been found from the Winza deposit. Although most are not facet quality. Low quality rubies found from this region are usually heat treated with lead glass.
1980s - Current
Mozambique is currently the largest supplier of Rubies to the world market. Some of the largest rubies were found here. Rubies from this locality tends to be richer in iron than Chromium. Although fine stones has been mined out of this region.
1909 - Current
Synthetic rubies have been in production since the early 1900s. The method was created by Verneuil and it's called the Verneuil flame-fusion method. Synthetic rubies made this way are widely available in abundance at a low cost. Today, there are advanced methods in creating synthetic rubies such as Hydrothermal and Flux. Synthetic rubies are mainly used to imitate their natural counterpart. Identifying a synthetic ruby can be performed by a trained gemologist through the use of standard gemological instruments.
Quality of Rubies by Origin
|5||Others (Vietnam, Afghanistan, etc.)|
The study of inclusions inside of a ruby is important for gemmologists because these minute clues can shine light on the identity of a ruby, where it came from and if it has been treated. Certain inclusions are only found from a specific source or mine site. Experts find these inclusions to pinpoint the origin of the gemstone be it natural or synthetic. There are the inclusions that are only found in rubies and never in any other gemstones. Such inclusions can be used to separate rubies from others. Finally, if the ruby has been heat treated, there are clues left behind from the heating process that can be revealed under a microscope. Visit our inclusions gallery here: Ruby Inclusions.
A discoid fracture around a dark coloured crystal , possibly zircon seen inside of an Unheated Burmese Ruby from Mogok.
A plane of unaltered three directional short rutile needles in an unheated Burmese ruby.
An elongated crystal, likely to be an apatite inclusion among multi-directional fine rutile needles. These are clear indicators that this Burmese ruby hasn't been heated.
Jagged 2 phased (liquid filled) fingerprint remains unaltered by heat in an unheated Burmese ruby.
An oval shaped crystal inclusion. possibly apatite, inside an unheated Burmese ruby.
Calcite crystal inclusion seen inside of an Unheated Burmese Ruby.
Twinning planes and a gas bubble can be seen inside this African glass filled ruby.
Three directional rutile needles of silver and red colour on the surface of a bi-coloured star sapphire from Mogok.
Historically Significant Rubies
The Timur Ruby which weighs in at 352.5ct and was believed to be the largest ruby in the world until 1851. The blood red coloured polished rough was found to be a red spinel. It’s named after the Persian king, Timur, who first ruled the Timurid empire across Central Asia and Persia. Inscriptions of names and dates can be found on the stone as it was passed down from each successor of the throne. In 1849 when the British colonised Punjab in India, the Timur Ruby along with the famous Koh-i-noor diamond was found together and was taken from the Lahore Treasury. The East India Company later gifted the stone to Queen Victoria in 1851. It was set into a necklace in 1853. It now remains in the private collection of Queen Elizabeth II.
Name inscriptions of Shah Jehan, the fifth Mughal emperor and his successors can be seen on the Timur Ruby along with the following statement: “This is the ruby among the twenty-five thousand jewels of the King of Kings, the Sultan Sahib Qiran (Timur).”
The Black Prince's Ruby
The Black Prince’s Ruby which currently is mounted on the Imperial State Crown of England is a red spinel despite the name ruby. It was thought to be a ruby until the discovery of a separate mineral called spinel in the late 1700s. The stone weighs approximately 170ct and is in the shape of a polished rough. The English monarchy acquired the gem as payment of war in 1367 through Edward of Woodstock (The Black Prince), when he helped defeat a rebellion against a petty king of Spain, Don Pedro. Since then, this spinel has survived through many battles being mounted on the helmets of English kings and now sits peacefully on the Queen’s crown. The spinel was probably mined from the famed Balas rubies mines of Tajikistan/Afghanistan formerly known as Badakhshan.
The Black Prince's Ruby can been seen here mounted above the Koh-i-noor diamond on the Imperial State Crown of England. There was once a hole drlled on to the spinel which indicates that it was worn as a pendant at some point in history. The hole has since been plugged with an actual Burmese ruby as seen in this image.
World's Most Expensive Rubies
The Sunrise Ruby
The Sunrise Ruby is the ruby that set the world record price for the most expensive ruby ever sold at auction. The 25.59ct Uneahted Burmese Ruby from Mogok sits on a platinum ring made by Cartier with two shield shape diamonds on its side. In May 2015, the ring was sold for $30,335,698 USD at a Sotherby's auction in Geneva.
The Graff Ruby Ring
8.62ct Burmese Ruby on the Gaff Ruby Ring was another record breaker at the time of the auction in 2014. It was bought back by Laurence Graff for $8,600,410 USD. It's currently for sale by Graff London.
Burmese Ruby Brooch by Cartier
In the same auction as the Graff Ruby Ring, this magnificent brooch featuring a 10.10ct Burmese ruby as also sold for $8,428,127 USD in Geneva, November 2014.
Burmese Ruby Ring by Cartier
A 29.62ct Burmese Ruby Ring was sold at an Sotherby's auction in Hong Kong for $7,379,953 USD in April 2014.
The Patiño Burmese Ruby Ring
The Patiño Ruby Ring was once a prized possession of Luz Mila Patiño, Countess du Boisrouvray and daughter of Bolivian tin tycoon Simon Patiño. Its centrepiece is a 32.08ct Mogok Unheated Burmese Ruby. In May 2012, it was sold for $6,736,750 USD at a Christie's auction in Geneva.
The Queen of Burma
23.66ct Burmese Ruby Ring dubbed the Queen of Burma was once own by Khengarji III, the Maharaja of Kutch in India. It was sold in 2014 for $6,084,559 USD, accompanied by a letter from Cartier that says it was purchased by His Highness the Maharajah of Kutch on 6 November 1937.
|Chemical Composition||Al2O3 Aluminum Oxide|
|Transparency||Transparent – Opaque|
|Specific Gravity||3.97 - 4.08|
|Reflective Index||1.762 - 1.770|
|Birefringence||0.008 - 0.010|
|Balas Ruby, Spinel Ruby, Rubicelle||Red Spinel|
|American, Colorado, Arizona, Adelaide Ruby||Red Garnet|
|Brazilian Ruby, Rubellite||Red Tourmaline|
|Ramaura, Chatham, Verneuil, Gilson Ruby||Synthetic Ruby|
|Inamori, Kashan, Zerfass, Kyocera Ruby||Synthetic Ruby|
About the Author
Wai was born and raised in Yangon, Myanmar (Burma). Trained by the Gemmological Association of Australia, he is a qualified Gemmologist. Throughout his life, he has been in constant contact with gemstones and jewellery through the family business and has been fascinated by the beauty and rarity of them all. He is now operating a branch of the business in Australia, supplying all kinds of gemstones especially of Burmese origin to international markets.
Last Updated 23/05/2019