Openworked white gold ring of 4g05 set in its centre with yellow oval cut sapphire 2,85cts

White gold : White gold is an alloy of pure gold with copper, Zinc, Palladium or nickel.
Modern cut : Cut made after 1919 according to the cutting rules described by "Marcel Tolkowsky" in his book "Diamond Design".
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.