Lot of 12 CupelsEach Cupel will absorb 69.2 grams of lead.Cupels are made from high quality dead burnt magnesia (MgO). Hard, smooth surface with consistency in weight and size. Provide exceptional results in gold mines, precious metal refiners, alloy melters, hallmarking, geological and test laboratories worldwide.CUPEL DIMENSION is 1-3/4" across the top & 1-7/16" tallThe lead button for cupellation is typically generated in the crucible fusion from the fire assay process, but can also be produced by a scorification assay, or a bullion assay where the precious metal is wrapped in lead foil.