1. small, shallow, porous cups made of bone ash or other refractory material, used in assaying to separate precious metals from base metals
Usage: metallurgy; chemistry

Examples

• The assayer placed the gold sample in one of the cupels for testing.
• Cupels are heated to high temperatures during the refining process.
• The laboratory ordered new cupels for their precious metal analysis.
• Silver was separated from lead using traditional cupels.
• The cupels glowed red-hot in the furnace during the assay procedure.