Clarity provides information about the visibility of inclusions. A distinction is made between extremely rare flawless diamonds and diamonds with inclusions. Many of these gradations cannot be perceived by the human eye - this is only possible from SI1. However, visible inclusions can also be covered by the setting and are no longer visible on the piece of jewellery later.
The carat number indicates the weight of a diamond. 1 carat equals 0.2 grams. For brilliant cut diamonds, the carat number can even be estimated by the size. Contrary to many beliefs, the carat number is not the only price indicator. This is built up taking all 4Cs into consideration.