Assay furnace is a heating device used in jewelry making. Assay furnace is available at jewelerstoystore to make the work easy for jewelry makers. Assay furnace is a heating device used in jewelry making. Assay furnace is available at jewelerstoystore to make the work easy for jewelry makers. Assay furnace is a heating device used in jewelry making. Assay furnace is available at jewelerstoystore to make the work easy for jewelry makers.