cupel
Concise Oxford English Dictionary © 2008 Oxford University Press:
cupel /ˈkjuːp(ə)l/
▶noun 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. ▶verb (cupels, cupelling, cupelled; US cupels, cupeling, cupeled) assay or refine (a metal) in a cupel.
– derivatives
cupellation noun.
cupellation noun.
– origin C17: from Fr. coupelle, dimin. of coupe ‘goblet’.
'cupel' also found in these Oxford entries:

