Ruby gemstones are those wonderfully rich red gemstones that are a variety of a mineral called Corundum. The deep red color of a Ruby Gemstone is due to the presence of a small amount of chromium that gives it its rich red coloration.
Ruby gemstones through the ages:
For thousands of years, Rubies have been associated with fire, energy, passion and love. Often referred to as the “king of gems” ruby gemstones have been seen as being in a class of their own, the symbol of powerful feelings. In Sanskrit, the ruby gemstone was valued as a rare and prized precious stone and known as ratanrajn; this is where the reference to the king of gems originates; the Latin word ruber, from which the ruby gets its moderns name, simply means red.
The other important element and association of a Ruby Gemstone besides fire is of course blood. Rubies are believed to restore vital life forces and increase energy and vigor. The Ruby is also known as the stone of courage; according to legend, a person possessing a ruby, can walk through life without fear of evil or misfortune.
French jewelers called the ruby the “gem of gems” – and sometimes the “dearly loved stone”. Ruby is spoken of in the Bible in the Book of Job and in Proverbs. Ruby is said to have adorned Aaron’s breastplate and was the symbol of Judah, while Christian leaders loved rubies right from the medieval period through to the present day. For much of this time, rubies were considered even more valuable than diamonds.
In Europe, rubies have long been associated with royalty and ruby gemstones have been used in coronation regalia for hundreds of years. However, gems like spinel and garnet were often confused with rubies. In fact, until 1800, all red colored gemstones were called rubies. As a result, many so called large precious rubies in the crowns of French and English monarchs have turned out to be spinels rather than true rubies. The most prominent stone of this kind is the “Black Prince’s ruby” which adorns the English royal crown; it is in fact a spinel. The other famous stone that was originally thought to be a Ruby is the Timur Ruby which is a 352 carat red spinel and is now owned by the British royal family.
One of the 4 major gemstones:
The Ruby Gemstone is considered to be one of the four main precious stones together with the sapphire, the emerald and the diamond. When the corundum has other impurities such a iron or titanium, it becomes blue and is called a Sapphire. In comparison, the emerald is a variety of the mineral beryl and obtains its green color from trace amounts of chromium and sometimes vanadium. Diamonds are a form of carbon, where the carbon atoms are arranged in a crystal structure (a diamond lattice) which gives the diamond its superlative physical qualities, most of which originate from the strong between its atoms. In particular, diamond has the highest hardness of any bulk material.
Myanmar (Burma) was for centuries the world’s main source for rubies – particularly the Mogok Valley in Upper Burma; this region has produced some of the finest rubies ever mined but, in recent years, very few good rubies have been found there.
Almost all of the rubies for sale today are described as “natural.” However the quality of these rubies varies. Many of the rubies on the market today have been heat treated or have undergone some form of chemical process designed to enhance their color or clarity. The value of these “treated stones” is significantly less compared with natural, untreated stones. Natural untreated rubies command a premium over treated stones. See our article on ruby gemstones – how to assess quality for more information.
In the pictures above, you can see the development of a ruby from its crystal form through to a natural gemstone with inclusions (blemishes) and then to a finished cut ruby gemstone. The ruby on the far right is a lab-created ruby unfit for jewelry. Synthetic rubies have technological uses as well as gemological ones; rods of synthetic ruby are used to make ruby lasers and masers.
The ruby at the top of the page is from the collection of billionaire Lily Safra. this was sold at auction for $6.74 million – making it the most expensive ruby ever sold.
Improving the quality of a gemstone using (usually) some form of heat treatment is now accepted as common practice. Many jewellers accept that heat treatment for rubies is now the norm and some form of heat treatment is used with most, if not all, rubies at the lower end of the market. This treatment is designed to improve color, remove purple tinge, blue patches and silk. Improvements obtained include color alteration, improving transparency by dissolving rutile inclusions, healing of fractures (cracks) and even completely filling them.
A treatment, which has become more frequent in recent years, is lead glass filling. In this process, the fractures inside the ruby are filled with lead glass (or a similar material); this dramatically improves the transparency of the stone, making previously unsuitable rubies fit use in jewelry.
In the picture on the left, the left hand picture shows untreated ruby crystals; then crystals on the right have been heat treated.
Rubies were one of the first stones to be artificially created and there are lab-grown rubies on the market today. Synthetic rubies can be created through numerous laboratory processes. While lab-created rubies have the same chemical elements and composition as natural rubies, they are neither valuable nor rare. Gemologists trained to inspect the minute inclusions within gemstones can easily tell a synthetic ruby from a natural one.
Color and Quality of Rubies:
Gemstone quality Corundum (a ruby) comes in all shades of red, including pink; all have traditionally been called rubies. However, in the USA, a minimum color saturation must now be met for a stone to be called a ruby, otherwise the stone will be called a pink sapphire. This distinction between rubies and pink sapphires is relatively new, having arisen sometime in the 20th century.
However, the line separating a ruby from a pink sapphire is not clear and the subject is highly debated. As a result of the difficulty and subjectiveness of such distinctions, trade organizations such as the International Colored Gemstone Association (ICGA) have adopted the broader definition for ruby which encompasses its lighter shades, including pink.
The value of a ruby is determined by the richness of its ruby red color. The brightest and most valuable red rubies are called pigeon blood-red and command a large premium over other rubies of similar quality.
For further information on rubies see our article Ruby Gemstones – How to Assess Quality.