A Shaligram stone, also known as Shaligrama Shila, is a sacred stone found in the Kali Gandaki riverbed or banks, a tributary of the Gandaki River in Nepal. It is a fossilized stone or ammonite that is believed to be a representation of Lord Vishnu, one of the principal deities of Hinduism. According to Hindu mythology, Lord Vishnu was cursed to become the Shaligram stone for betraying the chastity of the goddess Tulsi. The stones are believed to have divine powers and are seen as a symbol of good luck and prosperity.

The stones are worshipped by the Vaishnavas and are used to worship Vishnu in an abstract form, i.e., God without form as a Saligrama. Unlike murtis, Shaligram stones can be worshipped in individual residencies alongside temples, can be carried away from one place to another easily, and can be worshipped as long as the chakra inside it has not been broken or cracked. The Pranatoshani Tantra cites various varieties of Shaligram stones on the basis of shape, color, features of the chakra, and distinct markings like the vanamala.

In conclusion, the Shaligram stone is a sacred stone that holds a significant cultural and spiritual root in Hinduism. It is believed to be a representation of Lord Vishnu and is worshipped by the Vaishnavas. The stones are seen as a symbol of good luck and prosperity and can be worshipped in individual residencies alongside temples.