Art deco style gold ring with a green garnet and diamonds certificate

Carat : The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.
Gold : Because of the softness of pure gold, it is alloyed with silver, copper or palladium. The proportion of these other metals give yellow, white gold. Without precision, the gold used in jewelry is 18 K, corresponding to 75% pure gold.
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.
Garnet : Appelés dans l'antiquité escarboucles. Les Grenats sont des silicates alumineux ou calciques le plus souvent rose ou rouge mais aussi verts, orange, ou jaune. Les principales mines sont en Inde, au Kenya, à Madagascar, au Mozambique, au Nigeria, au Sri Lanka et en Tanzanie. Il ne doit pas être confondu avec le Rubis.
Size : Ring size. It is often possible to reduce or enlarge the size of the ring.