According to ancient metallurgy, metals are also meant as representatives of gods. As mercury (Parad) is considered or said to be the semen (seed) of Lord Shiva, likewise gold and coper is also the representative of Mata Parvati (Mahadevi).
MAKING OF SUVARNA RASLINGA WITH MERCURY (PARAD) AND COPPER. After undergiong the process of ASHTASANSKAAR (eight stages of purification) as per the 'Parad Samhita', mercury (Parad) is called as 'Siddhaparad or Agnibaddha Parad. Only such parad has the capacity to withstand at high temperature in the heating process, and only this agnibadhha parad has the power of converting copper into a yellowish golden metal. Copper is melted in the furnace at a very high temperature about 1050 degrees and at the same time mercury is also melted separately. When both the metals melt down, mercury is slowly poured into the crucible of molten copper. This process of mixing the two metals, results in a small explosion with a big crackling sound and thick smoke.The final result of this mixture is the new yellowish golden metal. This metal is again melted in the furnace at about 1050 degrees and then die-casted to make the Shivlinga. A Shivlinga made from this new metal is known as the ‘Suvarna Raslinga’ in Parad Samhita. After the final finishing treatments like grinding, buffing and polishing it is coated with a one gram gold plating which gives the shivlinga a golden look.