Rubies, with their vibrant hues of purplish red, have adorned royal treasures for millennia and remain highly desirable to the present day. In this piece, we explore their history and what sets them apart.
Burmese rubies have set the standard in quality for centuries; Burmese stones have always been scarce. In recent decades, various events contributed to the decline of the availability of Burmese rubies in the West. Similarly, Thailand and Cambodia are historically prolific sources but are now in decline.
The late 20th Century saw the discovery and high production of rubies originating from East African countries, particularly Madagascar, Tanzania and Mozambique. Although first associated with lower grade gems, today increasingly large numbers of fine quality rubies come from Mozambique. It has become common practice by some gem testing laboratories to apply the term “Pigeon’s Blood” to describe the colour of certain Mozambique stones, a term previously associated with the Burmese ruby trade. This contributed to the increase in popularity of Mozambique stones in the far Eastern market. Fine quality Burmese rubies, however, are very rare and are priced accordingly.
Another source worth noting is Greenland. Although known as a source of rubies for decades, it has taken years for the stones to become available to the global market. Responsibly sourced Greenlandic rubies are enjoying a warm welcome from different levels of the industry.
Colour is the most significant factor influencing a ruby’s value. The finest rubies have a pure, vibrant red to slightly purplish red colour. In most markets, pure red hues fetch the highest prices and rubies with tones of orange and purple are less highly valued. The colour must be the perfect balance between dark and light; a dark shade will dull the stone’s brightness, but a stone that is too light may be confused with a pink sapphire, (though these gems also enjoy their own separate following).
THE DIFFERENCE BETWEEN PINK SAPPHIRES AND RUBIES
Both rubies and pink sapphires belong to the same mineral family, (Corundum), though rubies are much rarer, and this has led to some debate in the gem trade about how to correctly identify the stones. Historically, the word “ruby” referred to shades of red, which included pink. Cultural differences also play a part, for example in some gem-producing nations such as Sri Lanka, pink coloured gems were always considered rubies.
Most of the world’s leading laboratories now use a controlled set of comparison stones called “Master stones” to determine whether a Corundum is a ruby, the laboratory grading its master stones on the principle that red must be the dominant hue. In the gem trade however, determining the dominant hue is subject to personal perception.
Rubies almost always feature inclusions, though the value of the stone will depend in part on how visible these inclusions are. Noticeable inclusions that reduce the transparency or brightness of the stone can lower the value dramatically.
Typical ruby clarity characteristics include thin mineral inclusions called rutile needles, also called silk; needles might be short or long and slender, and they might appear to be woven tightly together.
Some inclusions can contribute positively to a gem’s appearance. The presence of these rutile needles causes light to scatter across facets, illuminating them beautifully and spreading the colour more evenly across the ruby’s crown.
MARIA WALKER / Jewellery Manager