Introduction to Ruby (Download PDF Version)

Mineral – Al2O3 (Aluminum Oxide)
Mohs Hardness – 9
Refractive Index – 1.762-1.770
Specific gravity – 3.9-4.1

In Ancient times rubies were associated with power of life as it similarises to the redness of blood. Love, Passion, Anger & Fury, These are all associated with our emotions. Ruby means ‘King of Precious Stones’ in Sanskrit. It’s always been highly desired due to its rarity and also for superstitions reason particularly in Asian markets because it’s believed to be associated with beauty and wisdom.

Red in corundum is because of the presence of trace element chromium. Most priced and liked colour is the pigeon blood colour, but they usually range from orangy-red to purplish-red, with tones from very dark to light (sometimes close to as of rink Sapphire). Lack of another trace element, iron, in rubies makes the gem fluoresce and burmies rubies usually lack iron, therefore are more priced as it gives a glow effect.

Rubies come from various origins such as Burma (Myanmar), Thailand (Siam), Cambodia, Afghanistan, Tanzania, Kenya, Madagascar, Vietnam, Afghanistan, Tajikistan and Nepal and India. The rubies can be (iron present) Basalt Hosted or Marble Hosted and Thailand and Cambodia and Tanzania are of basalt regions and often give them a darker appearance because of the lack of fluorescence. 

It is common for ruby to be heated for enhancement of clarity and colour. It is a permanent reaction and is widely accepted. If a ruby is untreated, then this means it is rare and this commands a premium and recently the price of untreated rubies have sky rocketed. There are also residues (foreign substances) present commonly in rubies in the cavities and fissures. GRS grades them accordingly according to the amount of foreign substances present such as H(a), H(b), etc. This is a normal practice to enhance the clarity of the stone, and buyers should not be concerned about it being not natural. However in recent times some rubies have been heavily filled with foreign substances, oiled, dyed, etc and they imitate the look of Burmese rubies. These are often referred as “African Ruby” in the trade. It is the duty of the seller to disclose the treatments to the buyer.

Rubies also have unusual optical characteristics such as asterism, which results in start rubies. Minute inclusions sometimes gives a velvety effect often found in Burmese rubies and this is highly regarded. The amount of pleochroism (optical phenomenon in which the gem appears to be of different colours when observed at different angles) can be influenced by the cutter depending on which direction he fashions the rough at.

Rubies are very highly priced and regarded as both a fashion item and an investment. Their hardness is ideal for use in every kind of jewellery. There is a ruby guide (draft) available for everyone developed by various organizations and on requests we could send it to you.  We at Gandhi Enterprises disclose every treatment and maintain the ethical standards involved in the mining, cutting and fashioning of these gems. Our fine assortments for calibrated sizes, prompt service and our prices are a benchmark.