Emerald is green beryl colored by around 2% chromium (sometimes vanadium), while the deep-blue maxixe variety owes its color to a radiation-induced color center.
A beryl crystal from Malakialina, Madagascar measured 18 m long and 3.5 m in diameter, weighing about 380,000 kg.
When eyeglasses appeared in 13th-century Italy their lenses were cut from beryl because glass could not be made clear enough — the origin of the German word Brille.