Mary Ruzza,age 15, of Dotham, Ale., for her question

IS BERYL A VALUABLE GEM MATERIAL?

In certain varieties, the mineral beryl can be a valuable gem material. One of the most valuable of all gems is the emerald, a variety of beryl that is colored green by minute amounts of chromium.

Chemically, beryl consists of aluminum beryllium silicate It is the chief commercial ore of beryllium. Pure beryl is colorless and transparent.

Aquamarine, also a gemstone that can be valuable, is a blue beryl. It is more common than the emerald and therefore not as valuable. Golden beryl and morganite or rose beryl are even less valuable.

Colorless beryl is occasionally used an a gem under the name goshenite.

Beryl has a vitreous luster with little fire or brilliance and so its value depends principally on hardness, transparency and color. It crystallizes in the hexagonal system.

Crystals weighing over a ton are not uncommon. Hut crystals of that size are invariably opaque and imperfect and therefore valueless as gem material.