Silver signet ring with a large cabochon sapphire 15 cts

Cabochon cut : Means a polished dome shaped gemstone stone, without facet.
Color : White diamonds color range from D (colorless, the purest white) to Z (light color). D, E and F are colorless diamonds, G, H , I and J are near colorless , K and L are faint color, M to Z have a light color.
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.