Lord Shiva Says to goddess tulasi, please listen to my words which remove your sorrow. And Lord Hari (lord vishnu) also please listen. Because, i will say things which will brings happiness to both of you. Tulsi which wishes you have done penance, it is result of that. Therefore, how can it be other. So you have got boon according to that. Now, change this body and take heavenly form. And being like Laxmi always dwell with Sri Hari in Vaikuntha. The body which you throw will be a Greatest River name Gandaki. Due to my blessing you will get high importance in worship of god. Dear you will always reside with sri hari in heaven, earth and patala. And be best among pushpa (flower). You will live lonely with lord vishnu in vaikuntha.
The Gandaki river is able to provide religious value. And incarnation of lord vishnu become wife of salt ocean.
And lord vishnu, with your curse becomes form of stone and reside in gandaki river.
There million stone insect bites and make design of chakra (wheel mark). Due to its different design and character and blessed, it is known as Shaligram Shila. And its name is categorized like Laxmi Narayana. Vishnu Shaligram and Tulsi leaves putting together is very holy and he/she is blessed. We should not remove tulsi leaves offered in shaligram shila. And we should also not remove shankha /conch shell from Shaligram and tulsi. Good person who put together tulsi shaligram shankha he/she will be dearest of sri hari (lord vishnu).
Lord shiva said importance of tulsi shaligram and became invisible by making pleasure to lord hari and tulasi devi. Lord shiva went kailasha and listening to lord shiva words tulasi became very much happy. She changes her body and take a form of divine river and lord vishnu take her to vaikuntha (home of lord vishnu).
Listening to it anyone get blessing of god vishnu and is able to provide bhoga and moksha (salvation).