Carat, colour, clarity and cut describe different qualities.
Carat measures weight, rather than face-up size. Colour and clarity grades describe separate characteristics; cut also affects the way light returns from a diamond. Consider the proportions and appearance together. Al Zahra’s standard diamond quality is D–F colour and VS–VVS clarity, with design specific details shown on each product.
Does more carat weight always mean a larger-looking stone?
No. Shape and proportions affect visible dimensions. Compare measurements where supplied as well as carat weight.
Further reading: GIA’s diamond quality factors.