Chemically pure beryl is colorless, but trace elements give rise to green, blue and pink/red colors. The most important variety is green emerald (colored by chromium or vanadium), followed by blue aquamarine and yellow heliodor (both colored by iron) and pink morganite (colored by manganese). Some beryls fashioned as cabochons exhibit asterism (a star-shaped pattern of reflections) or chatoyancy (a “cat’s-eye” seen in reflected light).
Chemically pure beryl is colorless, but trace elements give rise to green, blue and pink/red colors. The most important variety is green emerald (colored by chromium or vanadium), followed by blue aquamarine and yellow heliodor (both colored by iron) and pink morganite (colored by manganese). Some beryls fashioned as cabochons exhibit asterism (a star-shaped pattern of reflections) or chatoyancy (a “cat’s-eye” seen in reflected light).
