Technologies included stone and copper drills, updraft kilns, large pit kilns and copper melting crucibles. Then cupellation, crucibles, scorifiers and muffle furnaces are described. Thus it is used in refractories, cermets and laboratory crucibles. These furnaces were made from stone and the crucibles from imported, highly-refractory clay. This left the thorium, which was cast into ingots in beryllia crucibles. This includes large amounts of slag pieces, litharge cakes, and crucibles and moulds. Some of the first ultrapure samples of gallium arsenide were zone refined in these crucibles. SiC is used in crucibles for holding melting metal in small and large foundry applications. Original boat crucibles, thick section rods and precursor samples exist. Alternatively, hand-held graphite crucibles can be used. These contained fragments of crucibles, pottery vessels in which metal was melted. Carbon could enter the iron by diffusing in through the porous walls of the crucibles. Triangular crucibles were then used to melt the brass for casting. Containers may be crucibles or boats made from foil. Some of these copper alloy crucibles were used in the making of bells.