Parad is Supreme element of the Universe , This is the Element of Lord Shiva as written in Vedas, Puranas, and old ancient Text Books of India .
 
 This is also used in Ayurveda Medicines by famous Brands like Baidyanath, Dabur, Patanjali etc. By using as medicine Parad removes all types of deceases and by doing Puja of Parad in a solid form in the Shape of Shivlinga this gives Moksha (Salvation). Worshiping Parad Shivling gives freedom from the sins of many Previous lives .
 
By establishing Parad Shivling in the house Lord Vishnu also becomes a Resident in that house because this is written in the Vedas and Puranas.Lord Vishnu and Lakshmi always resides in the place Where there is presence of Lord Shiva. This Parad Shivling is made of 8 Sanskar performed Mercury as described in Ras Sastra Text Books like Ras Tirangini, Ras Ratan Samuchchaya, Rasender Sar sangrah, etc.Sanskars are the eight purification stages of Mercury by doing them Mercury becomes divine and free from  doshas.