Diamonds are weighed by the carat. A one-carat diamond weighs about one-fifth of one gram. There are 100 points to a carat, 50 points to a half-carat, etc. Crystals lose about half their weight in the cutting and faceting process.
Polished diamonds increase in price exponentially by weight. Heavier diamonds cost more for two reasons: First, larger diamond crystals are rarer in nature. Heavier diamonds with fine cut, beauty, and rarity are much more expensive than smaller diamonds of equal quality. A one-carat diamond is about 4 times the cost of a half-carat, not twice the cost.
It is important to distinguish between diamond weight and diamond size. Size refers to the dimensions of the stone and belongs in a discussion about cut. There are diamonds that weigh 2 carats and are cut so they are smaller than diamonds that weigh 1.50 carats. The opposite is also true. There are diamonds cut with large flat surfaces that look like stones with greater carat weight. Both types represent poorly cut stones that are routinely sold in the jewelry industry.
Many times there are “price breaks” at certain weights of diamonds. A .90 carat diamond is much less expensive than a one carat diamond. A matched pair of diamonds for pierced earrings with a total weight of .94 carats is much less expensive than a matched pair that weighs 1.00 carats. Be sure to consult your jeweler for such price breaks. You can save hundreds, even thousands of dollars on your purchase.
Tom Tivol’s Best Advice: It makes no sense whatsoever for anyone to purchase a 1.50 carats princess cut diamond where the top surface of the diamond is so flat and the depth of the pavilion of the diamond so great that together they destroy any possibility of fire and sparkle, just to be able to say they bought a 1.50 carats stone. All that is present is carat weight, not what is most important to the staying power of the diamond – its beauty. Buying, owning, and wearing large diamonds is exciting, but only for those diamonds cut to display their maximum brilliance, fire and sparkle.


