As we’ve covered before, the price of a diamond increases exponentially as the carat weight of the stone increases. As you get into the higher carat weight categories, the price per carat for a diamond increases suddenly. 2 carat diamonds are certainly impressive, and this adds a premium to the price. We’ve explained how this phenomenon works more in our guide to how much diamonds are worth. This is due to several factors, the biggest of which is that larger diamonds are rarer than smaller diamonds and, as such, are priced at a premium per carat.