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