Shiva Puja must be performed with linga. The Rasalingam has a place in the worship of Shiva. Tamil Siddhas identify mercury as Shiva's metal (Shivadhatu). According to Siddha alchemy, mercury is the representation of male (Shiva) form, and the chemical element sulfur associated in the solidification process is considered as the representation of female (Shakti or Gauri, consort of Shiva) form.