Mallinga Kotibhi Drsthi Yad Phalam Pujiti | Salagrama Sila Yamtu Ekasyam Iva Tad Bhaved I | "The virtue obtained by seeing and worshipping hundreds of thousands of My Lingams, is equivalent to that obtained by worshipping one single salagrama sila."
The mark of Vishnu chakra is found on Shaligram. The chakra is seen distinctly on the Shaligram that opens by itself. In Shaligram which are closed, there are small holes which makes one comprehend that there is chakra in it.
According to Shiva Puran, the reasons of chakra's existence in shaligram is because once upon a time Brinda had cursed Lord Vishnu that he had turned into a black stone and worms would gnaw at him. Therefore a worm takes birth in Shaligram and nibbles it in spherical form. It is a marvel in itself.
By worshipping Shaligram an individual earns happiness, comfort, opulence and respect. A man who worships it, gets salvation.
Shaligram should never be placed instantly in the place of worship after buying it. Worshipping of Shaligram becomes more crucial if somebody else presents it to the worshipper. It a newly married couple worships the Shaligram presented by someone else, their conjugal life would be content and affluent.
Excerpts from Puranas
The Lord domiciles in several places in which he may be worshipped, but of all places Salagrama is the best. (Skanda Purana).
With Keshava in the form of Salagrama sila reside all the devatas, asuaras, yaksas and the fourteen worlds. (Padma Purana).
"In this mortal world, if anyone does not worship Salagram Sila, I do not at all accept any of their worship and obeisances".