Discription from the company website-

　　Made of cast iron, John Wright Lattice Steamers feature a resilient porcelain finish inside and out to resist rusting and chipping. Used for humidifying, steamers bring a pleasant fragrance to a room when filled with potpourri. Unique in design and of the highest quality, our steamers are functional as well as decorative stove accessories. Holds about 3 quarts of water for 8 or more hours of use under normal conditions.

　　instructions-/documents/Steamers%20Guide.pdf

　　For use on wood & coal stove.

　　Mine does have a small chip.

　　Price is firm.