The word 'diamond' comes from the Greek term 'adamas', meaning unconquerable.

The youngest diamond is 900 million years old.

Diamond is the hardest natural substance known to man. It is 58 times harder than the next hardest mineral on earth.

Diamonds are formed under extreme heat and pressure deep within the earth's crust, and come to the surface through volcanic eruptions.

80% of the world's diamonds are not suitable for jewelry.

Diamonds are the only gemstones composed of just one chemical element, carbon. Although crystal-clear, it is black when reduced to dust.

Diamonds can be completely consumed by fire at temperatures ranging from 1,400° to 1,607° F., depending on the hardness of the gem

In 1994, Pauline Willemse cut the world's smallest diamond. It was 50 times smaller than the head of a ballpoint pen.

The world's largest gem quality diamond, the Cullinan, was found in South Africa in 1905. Uncut, it weighed 3,106 carats (approximately the size of an ostrich egg). Known also as the Star of Africa, it adorns the scepter of King Edward VII of England and rests in the Tower of London.

Most expensive diamond: $16,548,750. It was bought in 1997 and was 100 carats.

Only a diamond can cut another diamond.

Diamonds exist in all colors - the rarest color being red.

The highest price paid per carat at auction for a diamond is £750,000 for a 0.95ct purplish-red diamond.

On May 13, 1888, using a pen encrusted with diamonds and emeralds, the Princess Imperial Regent Dona Isabel signed the decree ending slavery in Brazil. With a single stroke, she liberated 1,500,000 men, women and children, and brought freedom to the last slave-holding country in the western hemisphere.

If you were to gather all the diamonds ever polished since the beginning of time, they would fill only one double-decker bus.

The word 'carat' comes from the carob tree whose seed was used for centuries as the standard for weighing precious stones.

The 4 Cs , the characteristics by which a diamond's value is determined, were introduced in 1939.

It is believed that a diamond: endows the wearer with courage and fortitude; brings victory and good fortune; wards off evil; protects against the plague; promotes constancy in a marriage.

The custom of wearing a diamond ring on the fourth finger of the left hand comes from the ancient Egyptians, who believed that the vena amoris ("vein of love") runs directly from this finger to the heart.

A diamond's cut is critical to its final beauty.