Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form minerals. Notable gemstones high in beryllium include beryl (aquamarine, emerald) and chrysoberyl. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. The world's annual beryllium production of 220 tons is usually manufactured by extraction from the mineral beryl, a difficult process because beryllium bonds strongly to oxygen.
Beryl is often unknown to the general public. However, it is one of the most important gem minerals. Beryl is colorless in pure form; it is the many different impurities that give beryl its varied coloration. Without these splendid color varieties, beryl would be a rather ordinary gemstone with only average fire and brilliance. Emerald is the green variety and Aquamarine is the blue variety of beryl.