I stress categories, because you might mistakenly believe that prices per carat increase continuously as weight is increased, but this is not the case.
Since diamonds are a retail product driven more by emotion than reason, a 0.99ct diamond is worth only about 1% more than a similar diamond weighing 0.98ct. But a 1.00ct diamond is worth about 20% more than a similar 0.99ct diamond. Why is that?
Maybe because now you can say it’s a “one carat diamond,” or maybe because now it’s three full digits. Who knows. But with diamonds, it’s all about feelings. This little quirk about the business is the sole reason there are so many poorly cut diamonds out there.