Crucible /(krṳ"sĭ*b'l)/

Cru·ci·ble

Crucible

n.
  1. A vessel or melting pot, composed of some very refractory substance, as clay, graphite, platinum, and used for melting and calcining substances which require a strong degree of heat, as metals, ores, etc.
  2. A hollow place at the bottom of a furnace, to receive the melted metal.
  3. A test of the most decisive kind; a severe trial; as, the crucible of affliction.

Phrases & Compounds
Hessian crucible
a cheap, brittle, and fragile, but very refractory crucible, composed of the finest fire clay and sand, and commonly used for a single heating; -- named from the place of manufacture.