White gold ring 750 (18 carats) rubies and diamonds

White gold : White gold is an alloy of pure gold with copper, Zinc, Palladium or nickel.
Treated : Treated refers to a heating of a gemstone in order to homogenize and reinforce its color, but also to reduce inclusions. A non treated stone means a stone which has not been heated.
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.