1) Assay vessel 2) Bone-ash cup 3) Gold-assaying cup 4) Porous pot 5) Refractory pot 6) Vessel 1) Test 
goldsmith's vessel for assaying metal
• (v. t.) To refine by means of a cupel. • (n.) A shallow porous cup, used in refining precious metals, commonly made of bone ashes (phosphate of lime).
Cu'pel (kū'pĕl) noun [ Late Latin cupella cup (cf. Latin cupella , small cask, dim. of cupa ) : confer French coupelle . See Cup , and confer Coblet .] A shallow porous cup, used in refining precious metals, commonly made of bone ashes (phosphate...Cu·pel' (ku*pĕl') transitive verb [ imperfect & past participle Cupelled (-p?ld'); present participle & verbal noun Cupelling .] To refine by means of a cupel. 
A cupel is a receptacle made from bone-ash and used in cupellation.