An automotive lamp has a sealed envelope of barium silica glass that is essentially free of cadmium and in which a light emitting element is contained. Lead-in wires extend through the envelope and are coupled to the light emitting element. The glass envelope and lead-in wires have respective coefficients of thermal expansion over a temperature range form ambient to 520.degree. C. which closely match one another to minimize stress and cracking of the envelope at the interface.