Ruby red gemstone

Ruby is a red variety of corundum, one of the world's most valuable gemstones, known for its hardness and intense color.

About this subject

Ruby is a gemstone composed of aluminum oxide (Al2O3) with traces of chromium, which give it the characteristic red color. It belongs to the same mineral family as sapphire, differing only in color. With a hardness of 9 on the Mohs scale, it is one of the hardest natural substances, surpassed only by diamond.

Major sources of ruby include Myanmar (formerly Burma), famous for producing the most coveted 'pigeon blood' rubies, as well as Thailand, Sri Lanka, Mozambique, and Tanzania. Mining is often artisanal, with alluvial deposits. Natural rubies frequently contain inclusions; heat treatments are common to improve color and clarity.

Culturally, ruby symbolizes love, passion, and power. In ancient India, it was considered the 'king of gemstones'. It is the birthstone for July and associated with the zodiac sign Cancer. Large historic rubies, such as the Black Prince's Ruby (actually a spinel) and the Timur Ruby, are part of the British Crown Jewels. The largest ruby ever discovered is the 'Emperor Ruby', weighing about 450 carats.

Interestingly, the term 'ruby' derives from Latin 'ruber', meaning red. The most valued color is pure red with a slight bluish tint (pigeon blood). Synthetic rubies have been produced since the 20th century for industrial and jewelry use. The gem is evaluated by color, clarity, cut, and weight, with color being the most important factor.

Frequently Asked Questions

What differentiates a ruby from a sapphire?

Ruby and sapphire are both varieties of the mineral corundum. The difference lies in the color: ruby is red due to chromium, while sapphires can be blue, yellow, pink, or other colors, typically due to iron or titanium impurities.

What is the best treatment for a ruby?

Heat treatment is the most common and accepted, heating the gem to high temperatures to improve color and reduce inclusions. Unheated natural rubies are rarer and more valuable.

What is a 'pigeon blood' ruby?

It is the most valued color in rubies, an intense red with a slight bluish tint. Originating from Myanmar, this term describes the ideal color, which is extremely rare.