Beryllium is a naturally occurring metal which is found in beryl and bertrandite rock.
It is extremely lightweight and hard, is a good electrical and thermal conductor and is non-magnetic. Prior to 1951, it was used in fluorescent lamp work. Beryllium disease primarily affects the lungs. The disease occurs when people inhale beryllium dust or fumes. Skin disease with poor wound healing and rash or wart-like bumps can also occur.