18 kt white gold ring adorned with a 0.45 ct sapphire and brilliant-cut diamonds

White gold : White gold is an alloy of pure gold with copper, Zinc, Palladium or nickel.
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.
Carat : The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.
Sapphire : Sapphire is a gemstone of the family of the mineral corundum. The most famous color for Sapphire is blue, but trace amounts of other elements can give yellow, purple, orange, or greenish sapphires. In the case of chromium impurities in corundum it would be called a called a Ruby. Sapphires are found in Sri Lanka, Myanmar or Australia.