A discharge vessel or chamber for a high-intensity discharge lamp is provided, including a central body having a discharge space provided therein, two capillaries closing off respective end openings of the central body and an electrode positioned within each respective one of the capillaries. The central body and the capillaries comprise an alumina material or an alumina-based ceramic material. An average diameter of alumina grains in the central body is greater than an average diameter of alumina grains in the capillaries, and the average diameter of alumina grains in the capillaries is in a range of 10 m to 25 m.