White gold earrings set with emeralds

Diamond : In mineralogy, diamond is an extremely rare, precious and hard (named after the ancient Greek "unbreakable") metastable allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice.
Carat : The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.
Brilliant cut : The modern brilliant cut was developed by Marcel Tolkowsky in 1919. It consists of 58 facets (or 57 if the culet is excluded). It is the most popular modern cut because it provides maximized light return through the top of the diamond.
White gold : White gold is an alloy of pure gold with copper, Zinc, Palladium or nickel.