Why is a diamond so precious? Diamonds, of course, are rare, and anything rare has a high value. But rarity isn’t enough. A thing must also be desirable, and diamonds are very desirable, indeed.

A diamond’s capacity to reflect light gives it an appearance unlike anything else in the world. The diamond is also the hardest substance known to man. A thing of beauty that can last for thousands of years, it has come to be a symbol of enduring love and loyalty.

Diamonds are not naturally beautiful. They have to be worked on to be made beautiful. Diamonds in the rough form are found in all sizes and shapes and are rather dull in outside appearance. Experienced diamond cutters must examine each diamond carefully and decide how to bring out its beauty. Sometimes a diamond is sawed by a fast revolving disc impregnated with diamond dust. Only diamond dust can be used to wear down another diamond.

Most diamonds are sawed in two, and each half is shaped and cut into a round diamond called a brilliant. The facets, or little faces, are ground on a high-speed, cast-iron wheel impregnated with diamond dust and oil.

The facets are placed symmetrically, and the average brilliant is cut with 58 facets. The more facets, the greater the brilliance of the diamond. Diamond cutters have developed a whole series of shapes for cutting diamonds, such as the emerald cut, the baguette, the marquise, and so on.

Diamonds which are sold for jewelry may vary considerably in color and quality. Some colors are rarer than others. The most valuable diamonds are those tinged with red or blue, or those that are clear and colorless.