(1) Farbe: dunkelgrün, blaugrün, 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) Pleochroismus: The intensity of emerald's pleochroism varies with the depth of the color. The dark emerald can [...]
