Rubies are a red gemstone from the corundum family of minerals. Pure corundum is colorless, but the presence of chromium creates the red hues of rubies. The gems have formed slowly beneath the earth’s surface, with the process taking between 20 million and 30 million years.
Rubies are extremely strong, registering 9 on the Mohs scale of hardness; diamond tops the Mohs scale at 10. They also have excellent toughness and no cleavage (a tendency to break when struck). This makes rubies a great choice for rings and other mountings that will be subject to daily wear.
The word ruby is a derivative of the Latin word ruber, which means red. All rubies are red but the saturation of the color varies, and the gemstones can have orange, pink or purple tints
Rubies can be found all over the world, but the most important sources of rubies are in Asia and Africa. Historically, Burmese rubies from Myanmar (formerly known as Burma) are considered to be the most coveted rubies due to their rich red color. Rubies were first discovered in Myanmar as early as 2500 B.C., with the two most prolific deposits located at Mogok and Mong Hsu.
The best-quality Burmese rubies possess the perfect combination of intense color saturation, silk (a fine pattern of thin rutile needles that scatters light to brighten a gem’s appearance), and strong fluorescence. Top-quality rubies that have a red to slightly purplish-red or pinkish-red color and emit a softly glowing red fluorescence are known in the trade as Pigeon's Blood rubies.
| Rank | Country |
| 1 | Hong Kong ($968m) |
| 2 | United States ($684m) |
| 3 | Switzerland ($581m) |
| 4 | France ($512m) |
| 5 | Italy ($263m) |
*Source: Observatory of Economic Complexity
While all rubies are red by definition, there is a spectrum of colors within the ruby family. These include purplish red, orangish red, and pinkish red. Finding a matching pair of rubies can be very difficult. Not only do the stones have to have exactly the same color, they also have to match in hue, tone and saturation.
Rubies form in an environment of super-heated, mineral-rich waters with low silica and low iron. What transforms corundum into ruby is the presence of an element called chromium. Had the corundum met a different element it might have become a sapphire instead; iron, for example, would have created a yellow sapphire.
The presence of chromium creates a beautiful spectrum of red shades ranging from brownish red to a light red that is similar to that of ripe raspberries. The chemical compound of a ruby also makes it very durable. Corundum, which is the crystalline form of aluminum oxide, has an excellent hardness, second only to a diamond, and an irresistible brilliance.
Rubies can be a romantic addition to jewelry designs.
Rubies can be cut into many shapes and sizes. Various factors are considered when planning how to transform a rough ruby into one or more cut and polished gemstones.
The red gemstones have a close-packed hexagonal crystal structure. Certain gem cuts work better than others with this type of formation, which is why the most common cuts of ruby available on the market are ovals and cushions with brilliant-cut crowns and step-cut pavilions. Other cuts including pear, round, marquise, trillion and emerald are also available, although these shapes are mostly reserved for larger rubies.
Natural rubies typically contain thin mineral and crystal inclusions called needles. When the inclusion is rutile and needles are present in intersecting groups, the effect is called silk. The rutile silk causes light to scatter across the facets of the gem, making it appear lighter. These needles can also cause a gemological phenomenon known as asterism, which creates a star-shaped concentration of light when the stone is cut into a cabochon.
Rubies have been revered since ancient times, and have been particularly prized in Asian countries where they are seen as a symbol of protection and good luck. The gemstones were discovered as early as 2,500 B.C. in the Mogok region of Myanmar, formerly known as Burma. Stone Age tools were discovered at mining sites in Mogok, giving clues to the ancient history of ruby mining in the area.
In the ancient Indian language of Sanskrit, rubies are called ratnaraj, which can be translated as the ‘king of precious stones’.
Ruby is cherished for its dramatic red color. For thousands of years, rubies were considered the stone of love, energy, passion, power, and a zest for life; a symbol for powerful feelings.
One legend claims that the early Burmese civilization believed that if male soldiers went into battle wearing a ruby, it would protect them against opposing forces. Rubies were also believed to be a virility boost.
Ancient Indian civilizations believed rubies to be the fruit of the Tree of Life, a mythological tree that they believed connected the upper world, middle world and underworld. The deep red color, they said, came from the heated rays of the sun shining on the tree.
Legends of Ancient Greece suggested that rubies were created by fire, and that if you cast a ruby into water the liquid would boil. This led to the belief that rubies were generated by a fire from heaven, represented on earth as a lightning flash.
Despite the invention of synthetic rubies in the 20th century, natural rubies have remained a popular choice for fine jewelry. The Art Deco era of the 1920s and 1930s particularly favored the red gemstones, setting them in geometric designs as bold pops of color.
In the 21st century, the ruby remains a highly sought-after gemstone, particularly for its vibrant color and durability. However, due to its relative rarity, high-quality natural rubies can be quite expensive. This has led to an increase in the popularity of alternative stones, such as lab-grown rubies or other red gemstones like garnet or spinel, which can offer a similar look for a lower price.
In recent years, there has also been a growing trend towards sustainable and ethical jewelry. This has led to an increased demand for natural rubies that have been ethically sourced and responsibly mined. Many jewelry designers and retailers now offer certified ethically sourced ruby options to meet this demand.
An example of a vibrant Burmese ruby, set into an Art Deco-inspired ring.