Book Appointment
Marylebone, London

Ruby: the July birthstone

Loose rubies

Table of contents

Primary Item (H2)


The gorgeous red ruby is the birthstone of July, making it the perfect choice if you or your partner has a July birthday. But there are also many other reasons you might choose one of these beautiful gems. Indeed most of our customers looking at ruby engagement rings are drawn primarily by their stunning colour and by the fact that they are a little bit 'different', being a slightly more unusual choice than diamonds, sapphires or emeralds.

In this article, we explore the characteristics and appearance of rubies; their history and meaning; how to look after them; and many frequently asked questions about them.

Appearance and characteristics of rubies

Cushion cut ruby from Mozambique
Cushion cut ruby from Mozambique

Like sapphire, ruby is formed from a mineral called corundum (a form of aluminium oxide, Al2O3), and trace amounts of chromium give it its red colour.

Again, like sapphire, ruby scores 9 on the Mohs hardness scale, meaning it is well suited to withstanding everyday wear and tear (only diamond, at 10, scores higher), making a ruby engagement ring a practical option as well as a beautiful one.

The finest rubies are a pigeon blood red

The colour of a ruby is the first thing to consider and a significant factor in determining its value. Although everyone will have their own preferences for different reds, the most precious rubies are an intense, vibrant red, with a faint hint of purple, that are neither too dark nor too light — known in the trade as 'pigeon blood.'

Pidgeon Blood Ruby edited
Pigeon blood oval ruby

The precise colour of a ruby is defined in terms of its hue, saturation and tone: 

  • Hue refers to the shade of red. Rubies come in hues ranging from orange-red through pure red to purple-red.
  • Saturation refers to how intense the colour is; the more intense, the better.
  • Tone refers to how light or dark the stone is, with a medium tone (not too dark) generally considered the best.
Ruby Colour Chart 1
Ruby colour chart

Flawless rubies are exceptionally rare and valuable

Clarity is another factor that influences how valuable a ruby is. Most rubies have visible blemishes or inclusions, which can come in many forms: pinpoint or grain crystals; fine fibres of titanium dioxide (rutile), known as silk; long thin tubes filled with gas or liquid; feather-like cracks; and various others. The fewer inclusions there are, and the less prominent they are, the rarer and more valuable a ruby is.

Most rubies are heat-treated, but beware of other treatments

It is possible to improve the colour and clarity of rubies by heating them. This technique has been practised for hundreds of years and is completely stable (the enhancements are permanent). For this reason, heat treatment is widespread, and you should assume that a ruby has been heated unless you are told otherwise. Unheated rubies trade at a significant premium and will usually be supplied with a gemological certificate confirming no evidence of heat treatment.

Aside from heating, rubies can receive various other treatments. These include lead glass filling, flux healing, and beryllium diffusion, all of which disguise problems with a stone's colour or clarity and, in some cases, can cause structural weaknesses in the gem. All of these treatments significantly undermine the value of a ruby and should always be disclosed.

If a ruby seems unusually well-priced and you can't see any apparent problems with colour or clarity, then most likely, it has been subjected to one or more of these treatments. If you are in any doubt, you should get the stone checked by an independent gemologist — no reputable supplier would object to this request.

The history and meaning of rubies

The word ruby comes from the Latin word "ruber", meaning red. Rubies are mentioned several times in the bible, and in the first century AD, the Roman scholar Pliny included rubies in his Natural History, describing their hardness and density. However, the history of rubies goes back even further than this, with the July birthstone having been prized since antiquity.

Rubies were first found in Myanmar about 4500 years ago

Stone Age tools discovered in the Mogok region of Myanmar, formerly known as Burma, suggest that rubies may have been first discovered in the area about four and a half thousand years ago.

French explorer Jean-Baptiste Tavernier wrote in the 17th century of caves in Burma where the finest rubies were found, often alongside the bones of large animals of a prehistoric nature.

Myanmar has been a major producer of rubies since at least 600 AD, and Burmese rubies are still some of the most prized of all gems. That said, after the ruby mines of the Mogok region were depleted, production moved in the 1990s to the Mong Hsu region, which has tended to yield rubies that are typically of a lower quality than those from Mogok.

Madagascar and Mozambique are now major sources of ruby 

While rubies continue to be mined in Myanmar, the most significant producers now are Mozambique and Madagascar, and rubies are also mined in Afghanistan, Greenland and Tanzania.

Rough uncut rubies
Rough uncut rubies

From Myanmar, demand for rubies spread through Asia before reaching Europe

In India, in the ancient language of Sanskrit, ruby is called 'ratnaraj', meaning 'king of precious stones', and in the Hindu faith, the Mani Mala describes the Kalpavriksha, a divine tree that bears rubies as fruit.

During the 17th century, a French explorer and gem merchant, Jean-Baptiste Tavernier, travelled extensively in India and described how rubies were the most prized of all gemstones, with the negotiations for some of the finest rubies taking many months.

In China, records indicate that rubies were traded along the North Silk Road as early as 200 BC, and according to legend, the Chinese Emperor Kublai Khan (1215-94) offered an entire city in exchange for a large ruby of exceptional quality.

As trade routes were established between Europe and Asia, explorers such as Marco Polo in the 13th century were presented with the opportunity to bring rubies to Europe, and the July birthstone quickly became one of the most sought-after gems of European royalty and the upper classes.

Indeed, King Henry VIII (1481 - 1547) is seen wearing a necklace set with rubies in his most well-known portrait and, to this day, the British Crown Jewels include an enviable collection of rubies.

image 2
King Henry VIII shown wearing a necklace set with rubies

Many ancient 'rubies' are actually spinel and garnet

It was only in 1800, with the advent of reasonably advanced microscopes and spectroscopes, that ruby was identified as a variety of corundum. Before that date, several different red gemstones were all classified as rubies, including red spinel and garnet.

So it is that ancient 'rubies' have sometimes been discovered to be a different gem variety, as was the case for the Black Ruby of the British Crown Jewels, which it turns out is a spinel!

Until the 1940s, ruby was the most popular gemstone for engagement rings

For hundreds of years, rubies were the most popular gemstones in engagement rings, but in the 1940s, De Beers was looking to boost sales of diamonds, which had fallen during the Great Depression, and in 1948, the company came up with the unforgettable tagline "a diamond is forever". Then in 1949, a broadway production told us that "diamonds are a girl's best friend", and the rest, as they say, is history.

Ruby ring in platinum with diamond halo
A bespoke Ingle & Rhode ruby ring in platinum with a diamond halo

Despite this, the British Royal Family has continued to favour ruby engagement rings in recent times: Princess Margaret received a ruby engagement ring in 1960, and Prince Andrew gave Sarah Ferguson a ruby engagement ring in 1985.

Rubies were widely believed to hold supernatural properties

All rubies exhibit fluorescence, a natural property that makes them glow under ultraviolet light. However, some rubies have such strong fluorescence that they seem to glow even in daylight. This is likely to have inspired beliefs in rubies having inner light and fire: some believed that a ruby placed in water could cause it to boil; or that a hidden ruby could shine through fabric to reveal its presence.

Furthermore, the colour red, and by association the July birthstone, has long been associated with blood, and some early cultures believed that the ruby held the power of life itself.

For example, ancient Burmese warriors believed that rubies made them invincible in battle – but only if the rubies were inserted into their flesh (simply wearing rubies was not enough!). And ancient Hindus believed those who offered fine rubies to the god Krishna were granted rebirth as emperors.

There was also a Hindu belief that rubies should be separated into four castes, according to their quality, in case lower quality stones should contaminate and weaken the powers of higher quality stones. The highest caste was reserved for 'Oriental rubies', called Brahmin, believed to bestow perfect safety on their owner, allowing them to live in peace with their enemies.

Mediaeval Europeans wore rubies to guarantee health, wealth, and success. Regarding health, rubies were believed to relieve blood disorders, inflammation and worms. In terms of wealth, rubies were said to help you accumulate riches, including more gems. In terms of success, people believed rubies had the power to resolve disputes, and that if that didn't work, that they guaranteed victory in any conflict.

Other properties also attributed to rubies have included protection from lightning and storms, and the power to dispel evil thoughts, anger, sadness and jealousy!

How to care for a ruby

Rubies are durable gemstones that stand up well to wear and tear. Nonetheless, they are not indestructible, so we recommend removing and safely storing your ruby engagement ring if you're exercising or performing manual tasks.

You can clean your ruby at home with warm water and a splash of detergent, using a soft toothbrush, but avoid using any strong chemicals or abrasives that might leave a residue or damage the surface of your ruby.

If you damage your ruby, you should take it to your jeweller for a professional repair. A lapidary can often polish minor chips and scratches with very little loss of carat weight, but larger chips may result in the stone needing to be recut.


Are rubies rare?

Yes, rubies are one of the rarest gemstones; gem-quality rubies are significantly rarer than white diamonds.

What should I look for when purchasing a ruby?

The main factors that determine the value of a ruby are its size (measured in terms of its carat weight), colour (ideally an intense, vibrant red, with a faint hint of purple, that is neither too dark nor too light), clarity (the fewer visible inclusions, the better), and treatment (unheated stones trade at a significant premium, and treatments other than heat should be treated with caution). Aside from the value of the ruby, it is also important to ensure it comes from an ethical source that hasn't contributed to human or environmental exploitation.

Are rubies durable?

Rubies score 9 on the Mohs scale of hardness, making them second only to diamonds. They are not indestructible, but they are durable gemstones well suited to withstand the normal wear and tear experienced by engagement rings.

Where are rubies found?

Significant ruby deposits are found in Myanmar, Mozambique, Madagascar, Tanzania and Greenland.

Can rubies be lab-grown?

Yes, ruby was first synthesised in the early 1900s. Priced at a significant discount to natural rubies, lab-grown rubies tend to have a deep, rich colour that is very evenly distributed, and good clarity.

Are rubies expensive?

Yes, natural rubies command the highest price per carat of any coloured gemstone, and exceptional rubies often surpass white diamonds on a cost-per-carat basis.

What are ethical rubies?

Ethical rubies are sourced without human exploitation and with due care for the environment. For these reasons, Ingle & Rhode does not source rubies from Myanmar or Madagascar. Instead, we source beautiful rubies that can be traced back to their mines of origin in Mozambique, Greenland and Tanzania. Unless a ruby can be traced back to the country of origin, you cannot know whether or not it was ethically sourced.

What are star rubies?

Star Ruby

Like sapphires, rubies can exhibit asterism due to the presence of needle inclusions or rutile and sometimes hematite. These so-called star rubies are incredibly rare and highly desirable. Found in a wide range of shades of red, like star sapphires, they are cut into cabochons to display the star pattern and vary from semi-transparent to completely opaque.


The gorgeous red ruby is the birthstone of July, and a form of corundum, making it a hard-wearing gemstone and an ideal choice for an engagement ring. Indeed, until the 1940s, ruby engagement rings were favoured over diamonds.

Prized since antiquity, rubies were first discovered in Myanmar (formerly known as Burma), and demand for them spread through Asia before reaching Europe in the mediaeval period. In many cultures and traditions, rubies have been said to hold magical properties, but even those who dismiss such claims cannot deny the beauty and allure of this scarce and precious gem.

The most valuable rubies are an intense, vibrant red with a faint hint of purple, have no significant inclusions or blemishes visible to the naked eye, and have not been heated or subjected to any other form of treatment.

Ingle & Rhode sources stunning ethically-produced rubies from Mozambique, Greenland and Tanzania (while avoiding untraceable rubies and rubies from Myanmar or Madagascar on ethical grounds), meaning that you can be confident that all of our rubies have been produced without human exploitation or environmental destruction. Please get in touch if you have any questions. We'd love to hear from you!

David Rhode
Together with Tim Ingle, David created Ingle & Rhode to offer a better alternative to the traditional luxury brands. Since 2007, we’ve provided our customers with genuinely ethical engagement rings, wedding rings and fine jewellery – free from conflict diamonds, dirty gold and child labour. With more than 16 years experience in the jewellery industry, David has deep expertise in diamonds, gemstones and jewellery design and manufacturing.