What is a 1 carat black diamond worth?

What a 1-carat black diamond is worth varies according to the cut, type (natural/treated) and the demand and supply. Both natural and treated black diamonds increase in value as demand increases. It ranges from $100 to $3,000 per carat. On 1stDibs, you can find a variety of unique and designer black diamond jewelry & watches from different periods to choose from.