Definition of cupel in English:



  • A shallow, porous container in which gold or silver can be refined or assayed by melting with a blast of hot air which oxidizes lead or other base metals.

    • ‘We produce several capacity crucibles and cupels and only use selected virgin materials for production.’
    • ‘The metal in the cupel melts and will be observed to become smaller as the process proceeds.’
    • ‘Here, the area of the rock engravings is delimited, at its ends, by two big cupels engraved in the platforms of the rocky bank; both have been carefully engraved and are deep and well finished.’
    • ‘Absorption is facilitated by manufacture of the cupel from a porous material such as bone ash.’
    • ‘The cupel with the lead is placed back into the furnace and heated at 1000 degrees or so.’
    • ‘Once cooled, the bead is removed from the cupel and weighed.’
    • ‘As the samples become molten, the base metals, including the lead, vaporize or absorb into the cupels, leaving only the precious metal on top.’
    • ‘Ordinary bone ash, air dried cupels must be placed in the muffle close together in transverse rows, sufficiently far back for uniform temperature.’
    • ‘According to our shopper, the assayer would make up a tray of aged bone-ash, magnesium or cement cupels into which crushed ore along with a button of lead was added.’
    • ‘In a well-ventilated furnace, the lead melted, oxidized and passed into the pores of the cupel, leaving only a bead of precious metals.’
    • ‘On the other hand, the use of cupel keys is extremely economical, which is why fabricants use them in products where they are only used occasionally.’
    • ‘Think of the cupel as a small smelt to produce ore.’
    • ‘We found his crucibles and cupels, ceramics that these people used to test rocks to see if they contained any precious metals.’
    • ‘On cooling, the prill is carefully extracted from the cupel.’
    • ‘Extensive knowledge and experience are required in such matters as making the bone-ash cupels, fine proof gold and silver, testing acids, and other special examinations and operations.’
    • ‘Very ornamental, this cupel is an interesting mixture between wood and wicker.’
    • ‘Cupel tongs are adequate for moving bigger range of cupels used in ore analysis.’
    • ‘For a week or so, we had the theory, the cupels, the lead, and the traces of silver, but no gold.’


  • Assay or refine (a metal) in a cupel.

    • ‘A cupel or cupelling hearth in which precious metals are melted for trial and refinement.’
    • ‘Do you have a furnace capable of cupelling?’
    • ‘As far as the historical aspects are concerned, it is necessary to mention the Romanesque Baptistry and the adjacent cupelled boulder with Celtic engravings.’
    • ‘The lead button is cupelled to oxidize the lead leaving behind a dore bead containing the precious metals.’
    • ‘There are six steps in the fire assay procedure: splitting - weighing - mixing firing - cupelling - parting.’
    • ‘The plant consisted of a ‘double German cupola’, a German style cupelling furnace and two 4-foot wooden housed fans (one was a backup unit).’
    • ‘‘They sat down and cupelled about two-thirds of their galena before they realized that they were wasting their time,’ he said.’
    • ‘To extract the silver, the Greeks roasted the ore and then cupelled the molten metal.’
    • ‘The fire assay begins by combining your sample with pure silver and pure lead in a process called cupelling.’
    • ‘Some assay beads disappear, collapse, hide under the surface, or spread out flat while being cupelled, just as the last tiny bit of liquid litharge is driven off.’
    • ‘Gold and silver bullion that remains in a cupelling furnace after the lead has been oxidized and skimmed off.’
    • ‘The lead button produced is scorified and cupelled leaving a bead of precious metal.’
    • ‘The prill is cupeled as described above to determine the precious metal content.’
    • ‘After cooling the lead button is separated from the slag and cupelled at 1000°C to recover the silver (doré bead) plus gold, platinum and palladium.’
    • ‘Lead cube contains any precious values and is ready for cupelling.’
    • ‘The product is then cupelled to increase the dross to the range of about 50-65% by weight bismuth.’
    • ‘This quantity will be well worth working, provided the lead is abundant: Probably one pound of silver in a ton of lead would more than repay the cost of extraction, as lead yielding only four ounces to the ton is said to be profitably cupelled in Great Britain.’
    • ‘Then the drill filings from drilling in several parts of the brick are then cupelled and assay results determines the purity and thus the sale price to our hypothetical customer.’
    • ‘When cooled, the lead is separated from the glass and then cupelled.’
    • ‘I burned and crushed bones to make my bone-dust for cupelling, and thus provided made nearly forty assays, some of which were afterwards checked in Adelaide, in each instance coming as close as check assays generally do.’


Early 17th century (as a noun): from French coupelle, diminutive of coupe ‘goblet’.