Panchayatana form of worship introduced by Adi Shankaracharya has assigned one element to one of the five deities in Hinduism. Shiva is the embodiment of Pirthvi Mahabhuta (earth) among the five elements. The five elements are ether/space, air, fire, water and earth. The five deities in Panchayatana form of worship are Vishnu, Mother Goddess, Ganesha, Surya and Shiva.
In this concept, the five deities are worshipped in the form of sacred stones found in five holy rivers.
Shiva, the embodiment of Prithvi Mahabhuta, is worshipped in the form of Banalinga found in Narmada River in Madhya Pradesh.