DIAMOND

Books could be-and have been-written about the diamond. Diamonds are pure carbon, and the nearest relative is graphite. Yet, the hardness of diamonds of 10 on the Mohs scale makes them unique and desirable despite their high cleavage properties, while graphite is so soft that it is used as a lubricant. The hardness accounts for a word such as adamant, which comes directly from diamond, and means unyielding and inflexible.

White or colorless diamonds are the most valuable, although diamonds cover the spectrum in color. Only the best diamonds are used as gems, although "best" means "best in comparison," with the rest being used for a vast range of industrial purposes.

Diamonds, like gold, are found on the surface near rivers or streams, on beaches, and deep within the earth. The surface diamonds are naturally the first to be found and lead to the digging of mines. Almost all diamonds nowadays come from mines.

About 1 G tons of rocks will produce several small diamonds adding up to 1 carat, but 250 tons must be processed to produce a single rough diamond large enough to be cut into a 1-carat stone. In proportion much more than 250 tons of rock is needed to produce even large, stones. Thus, a 1-carat stone is much more expensive than two 0.5-carat stones, and a 2-carat stone is more than twice the price paid 1-carat gem.

In addition, according to one expert, flawless stones get increasingly rare the deeper the mines are, which is why there may be no more top-quality, large stones in another thirty or forty years. As 1is, top-clarity and top-color stones account for only 2 percent of a diamonds.

The value of a diamond is determined by the "four Cs"-carat weight, color, clarity, and cut. Which is more important can depend on to whom you talk. How large a diamond you buy can depend on your pocketbook, but the best investment is usually a brilliant-cut diamond (see Chapters 3 and 5) since other cuts can depend or fashion.