A lamp and methods of forming are shown. In one example, a dielectric layer is formed over a gap between conductors in a plasma lamp. Electric arcing is reduced or eliminated, thus allowing tighter gaps and/or higher voltages. In one example a glass frit method is used to apply the dielectric layer. A lamp is shown with a barrier layer that prevents tarnish such as tarnish from sulfur exposure. The barrier layer reduces or prevents degradation of the lamp due to conversion of a conductor material to non-conductive tarnish material.