Ruby is the red variety of the mineral species Corundum, which also includes sapphire. So we understand that two of the most important coloured gemstones are essentially two varieties of the same mineral.
The colour of ruby comes from trace elements of chromium that enter the crystal during its growth in nature.
Rubies are ancient materials. The natural creation of rubies in the earth is a process that can take over twenty million years and requires very specific and stable geological conditions of pressure and temperature, as well as the continuous supply of the necessary chemical elements, and the absence of silicon, which is one of the most common chemical elements in the Earth’s mantle.
Rubies are very durable stones, and in terms of hardness-(i.e. the resistance of a material to surface wear – such as abrasion and scratches); come second to diamonds. They also have good resistance to breaking and good colour stability, especially when untreated. These natural properties of rubies make them an excellent choice for jewellery that is worn for many hours, or for settings in which the stone is relatively exposed to impact, such as rings.
Rubies are one of the most important stones historically, a story shrouded in mystery, glamour and passion. They had been given the title “the king of gems” and were a stone of great importance for all cultures. There were some periods when rubies had become more valuable even than diamonds.
As it is a gem that has accompanied people since the depths of time without ever losing its popularity, we find rubies in jewellery of all periods and in all styles, from traditional Indian jewellery, to impressive Art-Deco creations or strung together with diamonds and other gemstones in jewellery from 1800-1900, to modern and high-end pieces of fine jewellery.
The Roman scholar Pliny wrote in Naturalis Historiae about rubies, commenting on their durability, density and their wonderful red colour, which he described as “noble fire”.
It is said that the Chinese Emperor Kublai Khan offered an entire city to obtain a ruby of considerable size and high quality.
The explorer Marco Polo described the Asian ruby mines and the mining methods he discovered on his travels, while Jean Baptiste Tavernier wrote about the gem trade in India and the fact that rubies were the most valuable stones of all. He also reports that some arrangements for possible ruby sales could take months.
The European aristocracy of the Middle Ages and the Renaissance loved rubies, for the acquisition of which they spent exorbitant amounts of money or gold. Even today, ruby is the stone that can command the highest price in the carat than any other coloured gemstone.
Traditional sources from which rubies are extracted are found in Thailand and Myanmar where they were discovered in 2500 BC, Afghanistan and Sri Lanka among others, but also in East Africa, Mozambique and Madagascar.
Eva Kountouraki GG, AJP, JBM
Gemology Instructor, Jewellery Consultant
