Shaligram(Fossilized seashell stones)

Fossilized seashell stones are called salagrama, and serves as non-anthropomorphic symbol of Vishnu.

Salagrama or Shaligram refers to a fossilized shell used in South Asia as an iconic symbol and reminder of the God Vishnu as the Universal Principle by some Hindus.^[1]Shaligrams are usually collected from river-beds or banks such as the Gandaki river in Nepal.^[2] They are considered easy to carry and popular in certain traditions of Vaishnavism, as an aniconic representation of the divine. They are typically in the form of spherical, black-coloured Ammonoid fossilsof the Devonian-Cretaceous period which existed from 400 to 66 million years ago.