Beryllium

A low-density, gray metal used in many industries because of its high permeability to x-rays, light weight, and high tensile strength. It is also used in aerospace structures and inertial   3-4 guidance systems. It is highly toxic; death may result from ingestion of very low concentrations of the element and its salts. Beryllium compounds can enter the body through inhalation of the dusts and fumes, and they may act locally on the skin.