(1) Couleur: dark green, bleu-vert, and yellow-green are common. Among the single crystal gemstones that are also green, the green of emerald is bright, pure and soft. (2) Absorption spectrum: shows the typical spectrum of chromium-colored gemstones. (3) Pleochroism: The intensity of emerald’s pleochroism varies with the depth of the color. The dark emerald can […]