crucible

/หˆkษนuห.sษช.bษ™l/
noun
  1. 1

    A cup-shaped piece of laboratory equipment used to contain chemical compounds when heating them to very high temperatures.

  2. 2

    A heat-resistant container in which metals are melted, usually at temperatures above 500ยฐC, commonly made of graphite with clay as a binder.

  3. 3

    The bottom and hottest part of a blast furnace; the hearth.

  4. 4

    A very difficult and trying experience, that acts as a refining or hardening process.

Source: https://en.wiktionary.org/wiki/crucible