In Tibetan literature, the metaphor of gold smithery is used to describe knowledge specifically that, unlike the description of knowledge or wisdom as a process that occurs naturally, this metaphor describes knowledge as something that must be transformed from its natural state and shape.  First, it must be burned, that subjected to a physical process that brings out its physical, that is to say, chemical properties, such as melting point, boiling point, and such like.  Subjection to heat identifies a substance and separates it from other substances.  When heat has rendered a substance from a solid to a liquid state of matter, first, more volatile substances have been transformed into a gaseous state and have, by means of the energy imparted by heat have moved away from the liquid.