Ruby Gemstone Guide – Price, Quality Factors & More!

If you are reading this, then I’m guessing you want to learn more about Rubies?

Awesome, you have come to the right place as in this guide, I go through all of the things you need to know about these amazing gemstones and whether you are looking to learn or thinking about buying a Ruby, the information below will be useful to know, so let’s get started…

Quick Ruby Facts:

  • Ruby is the Birthstone for July
  • Ruby is the gemstone for the 15th and 40th Wedding Anniversary
  • Ruby is part of the Corundum family of gemstones, which also includes Sapphire
  • Rubies are the most expensive coloured gemstone, with top-quality examples only being beaten by Diamonds
  • Rubies are rarer than Diamonds

Ruby Properties and Origins

I’m not going to get too scientific here but the properties of Ruby are one of the reasons why it is such an amazing gemstone (and one of my favourites!).

As I said in the facts section above, Ruby is part of the Corundum family of gemstones, which also includes Sapphire. Corundum is Aluminium Oxide (AI2O3), which in its purest form is colourless

The red colour in Ruby is caused by the presence of Chromium (for you gem geeks, Chromium is also what causes the green colour in Emeralds).

Let’s stop with the chemistry lesson and look at the physical properties of Ruby as they are durable gemstones and a good alternative to Diamond for engagement rings as they have the following properties:


Rubies have a hardness of 9 on the Mohs Hardness scale.



Rubies have good toughness but are more likely to fracture than Sapphire.


Rubies are very stable.

If you aren’t sure what I mean by these terms, I’ve covered them below:

  • Hardness – this how hard the surface of the gemstones is
  • Toughness – this is how strong the stone is in terms of the stone breaking or fracturing
  • Stability – which is how well the stone deals with physical and chemical changes such as heat, light and exposure to chemicals (things like cleaning products etc)

So Rubies a durable gemstone but not quite as durable as Sapphires but why is this?

Simply, it is down to what makes Rubies different from Sapphires, the colour as Chromium is quite a large element and causes issues with the crystal structure, which is why Rubies are more likely to have fractures in them than Sapphires.

Where Are Rubies Found?

Rubies are found in many countries around the world, including Myanmar (Burma), Thailand, Mozambique, Sri Lanka, Madagascar and Tanzania.

When it comes to the origin of Rubies, some locations are more desirable than others and this can have a big impact on the price of a stone, some desirable locations are:

  • Myanmar (Burma) – the most famous and desirable location for Rubies, especially ones from the Mogok region and they are always called Burmese Rubies after the country’s previous name and many believe the best Rubies and ones with the true ‘Pigeon Blood’ colour come from here
  • Mozambique – now the largest Ruby producing country in the world and it terms of quality, many believe that they rival those from Burma
  • Thailand – historically a very important Ruby producing country and prior to the discovery of Rubies in Mozambique, Thai Rubies were only behind Burmese in terms of desirability and demand

The Ruby deposits found in many countries are quite small, meaning they don’t produce that many gem-quality stones every year.

Thailand is an interesting one as not only have Rubies been mined there for over 100 years but they are also the leading cutting and trading centre for Rubies and many of the world’s Rubies will probably have passed through there at some point.

Ruby Price

Ruby prices can vary massively from less than $50/carat to over $1,000,000/carat due to the large number of factors that affect the price of a Ruby, including:

  • Colour
  • Clarity
  • Weight
  • Whether it is natural or synthetic
  • The origin of the stone
  • Whether it has been treated
  • Style of Cut & Cut Quality
  • If the stone comes with a lab report

This is why it is nearly impossible to give any kind of guidance on Ruby prices online and prices are determined on a stone-by-stone basis by people who understand the Ruby market.

In the Ruby Quality Factors section below, I will look at some of these sections in much more detail and explain how these factors impact the price of Ruby.

Ruby Quality & Price Factors

Now we know what Rubies are and where they come from, let’s take a look at the quality and price factors as these all play an important role in how much a Ruby is worth!

Ruby Colour

When we are talking about colour in Rubies, we are talking about the quality of the colour and this has a big impact on the price of the stone as the better the colour, the more desirable it is, making it more valuable.

But what do I mean by the quality of the colour?

Well, there are a few things to consider when looking at colour in Rubies, which are:

  • Hue – this is the main body colour of the stone and ideally, this will be pure red but Rubies can have secondary tones of orange, blue, purple or pink, which aren’t as desirable
  • Tone – this is how light or dark the stone is and Rubies can range from light pinkish red to a very deep maroon colour, with stones falling in the middle of this range being the most desirable
  • Saturation – this is how evenly the colour is spread across the stone and good quality stones will have a nice even colour distribution

As you can see, there is a lot to consider when it comes to colour quality in Rubies and many people refer to stones with top-quality colour as ‘Pigeon Blood’, although some say this should only be used with Burmese Rubies.

The Graff Ruby (pictured) is one of the finest examples of a ‘Pigeon Blood’ Ruby and the rich, vibrant colour is what most people think of when they picture a Ruby.

But this colouration is extremely rare in natural, untreated Rubies.

The Graff Ruby

Ruby Clarity

Clarity is up there with colour in terms of importance and plays a big factor in how much a stone costs, if you aren’t sure what I mean by clarity, this is how free the stone is from inclusions and blemishes.

Good Clarity

  • The Ruby is transparent/translucent
  • Inclusions aren’t obvious to the naked eye
  • Any inclusions don’t detract from the beauty or durability of the stone

Poor Clarity

  • The Ruby is opaque
  • Inclusions are noticeable to the naked eye
  • The inclusions impact the beauty and/or durability of the stone

In general, Rubies are more likely to have inclusions than Sapphires, which is why ‘clean’ stones do fetch a premium but not all inclusions are bad as some can be used to identify the origin of the stone and also whether or not it has been treated.

But there is one exception to the clarity rule and that is Star Rubies.

On paper, they don’t look very appealing as they are opaque and heavily included, the colour also isn’t usually the best but

These stone possess a phenomenon called asterism, which is where light reflects off rutile inclusions that form parallel to the natural crystal faces and produce a 6 rayed star when looked at, such as the one in the picture.

These are highly desirable among collectors.

Star Ruby (Img Credit: GIA)

Rubies Are NOT Clarity Graded

Unlike Diamonds, Rubies are not clarity graded by gemmologists or gem labs, so be aware of anyone selling a Ruby who is using Diamond clarity grades such as SI or VVS to describe the clarity of a Ruby.

Ruby Cut

The next quality factor is cut and just like colour, this is broken down into two parts, which are the style of the cut and the quality of cut.

Style of Cut

Even though there are plenty of different cut styles, the majority of Natural Rubies are cut into one of three styles, which are:

  • Oval
  • Cushion (including elongated cushions)
  • Round

There are a few reasons why these three styles are the main options for stone cutters:

  1. They often generate a good yield from the rough crystal
  2. They help bring out the colour in the stone
  3. They are timeless styles that don’t really go out of fashion

Smaller Rubies may be cut into squares or marquise cuts but larger stones are usually one of the three listed above unless a certain style of cut has been requested by a client.

Quality of Cut

While the style of cut does play a part in the value of the stone, the quality of the cut is more important as it can be the difference between the stone looking amazing or dull and lifeless.

But most Rubies are cut as a compromise between optimising the colour and beauty of the stone and retaining weight as generally, the heavier the stone, the more it costs.

When it comes to the quality of the cut, there are some things that determine whether it has been cut well or poorly, these include:

  • Proportions – have the crown and/or pavilion been cut too shallow or deep
  • Facets – are they properly aligned and have crisp edges
  • Table – is the table in the centre of the stone
  • Girdle – is a straight and even or wonky
  • Polish – are there polishing lines of the facet faces

For top quality stones, they are usually cut to a very high standard and these things aren’t an issue but as the price per carat starts to drop, usually, the quality of the cut does as well.

Ruby Treatments

Rubies with good colour and clarity are very rare in nature, with these stones attract a premium and there are not enough of these stones found to satisfy the demand in the marketplace.

This is why the majority (over 90%) of Rubies for sale at any one time have been treated in one way or another and there are a number of different ways that Rubies can be treated, all of which have an impact on the value of the stone, the three most common Ruby treatments are:

Heat Treatment

The oldest and most accepted treatment of Rubies is heat and while the goal of Heat treatment depends on the stone it can be used to:
• Make stones lighter or darker
• Remove undesirable hues or colour zoning
• Improve clarity

Heat + Flux

A modification of the traditional heat treatment is to add flux to the process (usually borax) as the flux can help to partially heal surface-reaching fractures, which makes them less noticeable.
As with heat treatment, the results are permanent but it should be disclosed.

Glass Filling

Glass-filling is done to very low-quality material with the goal being to fill and reduce the appearance of fractures within the stone.
This is done by heating the stone in the presence of lead-glass powder, which melts and fills the fractures.
While it makes stones look better, the treatment isn’t permanent and can easily be removed and should always be disclosed.

In terms of price, how the Ruby has been treated does have a big impact but it is assumed that all Rubies have been heat-treated, which is why this is rarely disclosed.

But for all other treatments, they should be disclosed and as for prices, the following list should be helpful:

  • Untreated Rubies – these attract the highest premiums due to their rarity, especially if the stone has good colour and clarity and they should always be accompanied by a lab report from a reputable lab stating this
  • Heat-Treated Rubies – these sell for less than their untreated counterparts and as the majority of Rubies on the market have been heat-treated, a lot of pricing is based around heat-treated stones
  • Heat + Flux Rubies – these sell for less than Rubies that have just been heat treated due to the additional treatment that has taken place
  • Glass-filled Rubies – these ‘Rubies’ (some are more glass than Rubies) often sell for less than $50/carat as they are very low-quality and honestly should be avoided

This is where lab reports can be very useful as reputable labs will test the stone for treatments and will report their findings as to if the Ruby has been treated or not and what the treatment was.

Synthetic & Glass Filled Rubies
Lab-Created Ruby and Glass Filled Ruby

Natural vs Synthetic (Lab-Grown) Rubies

Whether a Ruby is natural or synthetic can have a huge impact on the price of the stone, especially if they are of similar quality.

For example, the synthetic Ruby in the image above can be bought for less than $10/carat but a natural of the same size and quality would easily be over $1000/carat and could be over $10,000/carat if it hasn’t been treated.

If the stone is being sold as a Ruby, then it is assumed that the stone is natural as all synthetic stones state that is synthetic, man-made or lab-created so that you as the buyer know that it isn’t a natural Ruby.

Lab Reports

Lab Reports are an important document but not every Ruby will be sold with a report as unlike Diamond reports, they don’t give any information about the quality of the stone but they do include some very useful information, which can include:

  • The stone, size, weight etc
  • The identity of the stone
  • Whether the stone is natural or synthetic
  • If the stone has been treated or not
  • The origin of the stone (it is not possible to do this on some stones)

And a report from a reputable gem lab, such as the GIA, Gubelin, SSEF, IGI or Anchorcert is essential if the seller is claiming that the Ruby is untreated and from a specific location.

Just a quick note, the labs mentioned above only produce reports, they never produce certificates. If you ever see a Ruby with documentation that says certificate or certificate of authenticity then run away as fast as you can!!

Ruby Gemstone FAQ

A good quality Ruby will possess a combination of a rich red colour, good clarity (eye clean with minimal inclusions) and good cut quality.

The most valuable colour of Rubies is know as ‘Pigeon Blood’, this is a pure red colour and is especially prized in Mogok Rubies from Burma. Rubies with a slight purplish tint are valuable but less so than pure red. Stones with a strong purple or orange overtone are less valuable.

Rubies vary in cost per carat and it all depends on the quality of the stone but it can range anywhere from less than $100/ carat to over $1 million/carat.

The most popular cuts for Rubies are Oval and Cushion as they produce the best yield from the rough crystals. With smaller stones (less than 1ct), Round, Square and Pear are also popular options.

There isn’t a defined point where a stone goes from a Pink Sapphire to a Ruby, it is all down to individual interpretation of the colour of the stone.


I know this is a bit on the bulky side but I have covered everything that I think you need to know when learning about Rubies from their origin to the quality factors and lots in between.

If you are looking to buy a Ruby, then some tips I would give are:

  1. Always buy from reputable dealers
  2. If they are claiming the stone is untreated or from a desirable location such as Burma, then make sure it comes with a report from a reputable lab to back this up
  3. Buy the stone you like, it might not be ‘perfect’ but if you like it, then it is the right stone for you
  4. But always avoid glass-filled Rubies as they probably won’t stay looking like that for long!

I'm Paul Haywood FGA DGA, the owner and founder of Haywoods Gems, I'm a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain.

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