It is a common mistake to think that the carat weight of a diamond is its size. Actually, carat weight is how much a diamond weighs, and while there is an increase in size for an increase in weight, the carat measure does not quantify a stone's size. Carats are more or less equivalent to two hundred milligrams, slightly less than one quarter ounce. Carats are also divided into one hundred points. Therefore, seventy-five points is the same thing as saying three quarters of a carat.
As the carat rating of a diamond goes higher, the relative rarity of the stone increases. Rareness is a good measure of price, but the relation is not linear. The price increases geometrically, which is to say that a two carat diamond will be worth more than two one carat diamonds. Or that one 50 point diamond will be worth more than double two 25 point diamonds. All these examples, of course, assume that the stone's are identical in every way other than weight.
Another thing that can affect the value of a stone is how it is cut. Gem-cutters can choose to emphasize certain qualities, but doing so can affect others. And just because two stones have the same carat rating does not mean that they will be cut in the same way. Generally, a stone that is cut to be wider and flatter will appear larger than its carat rating would imply. But this shape can decrease the stones luster by harming its brilliance or scintillation.
And if a diamond is cut too thin, it will lack all sparkle, which would effectively ruin it. The appearance of size, and hence carat weight, can be important, but there is no call to harm a stone's other qualities for the semblance of increased carats. When choosing a stone for yourself or a loved one, consider more than the dead quantity of carats. Each diamond is a microcosm of light and color, and should be evaluated as such.
If you come across a striking smaller diamond and are hesitating from purchasing it because of its meager carat value, remember that stones can always be improved with accessories like baguettes, trillians, or similar shaped stones one either side. As you might recall, the price of diamonds increases at a geometric rate as carat weight goes up. So you will be able to get two stones that weigh the same as one single stone. Use this to your advantage, and create a magnificent ring or necklace, if paying for a single high carat stone seems too pricey. So now you're an educated diamond connoisseur so go out and start shopping!