 Pure beryllium metal did not become readily available until 1957 , even though it had been used as an alloying metal to harden and toughen copper much earlier . Beryllium could be produced by reducing beryllium compounds such as beryllium chloride with metallic potassium or sodium . Currently most beryllium is produced by reducing beryllium fluoride with purified magnesium . The price on the American market for vacuum @-@ cast beryllium ingots was about $ 338 per pound ( $ 745 per kilogram ) in 2001 . 
