Patent ID: 7012375

Claim:
A thallium-free metal halide fill for a discharge lamp, the fill comprising: mercury, sodium iodide, an alkaline earth iodide selected from calcium iodide, strontium iodide, barium iodide, or combinations thereof, and a rare-earth iodide selected from cerium iodide, dysprosium iodide, holmium iodide, thulium iodide, or combinations thereof; wherein the molar ratio of sodium iodide to alkaline-earth iodide is from about 0.6 to about 11, the molar ratio of sodium iodide to rare-earth iodide is from about 0.5 to about 2.8, and the molar ratio of alkaline-earth iodide to rare-earth iodide is from about 0.1 to about 2.