Emerald is a chromium-containing emerald green beryl, usually together with diamonds, rubíes y zafiros, it is listed as the four most precious gems. The ancient Roman naturalist Pliny (Gaius Cecilius Secundus, acerca de 23-79 ANUNCIO) once gave a wonderful description of the color of emeralds: “There is no gem that is more pleasing to the eye [...]
