Beryllium is a relatively rare metal in the universe, often forming as a product of cosmic ray spallation.
Core Principles & Analysis
Louis-Nicolas Vauquelin discovered beryllium in 1798 while analyzing beryl and emerald, and Woehler and Bussy independently isolated the metal in 1828.
It is remarkably stiff for its low density and is nearly transparent to X-rays, though its dust and soluble salts are highly toxic to inhale.
Beryllium forms the windows of X-ray tubes, the gold-coated primary mirror segments of the James Webb Space Telescope, and non-sparking beryllium-copper tools for hazardous environments.