Do Scriptures confirm about the "Swayambhu" nature of Shalagramas and Banalingas?

Question

One can refer to this related question to know which are the 5 "Swayambhu Silas" or what is meant by a "Swayambhu Sila".

Hindus believe that Gods are present(naturally,without any human interventions) in certain stones and fossils found in some sacred rivers.

It is believed that Pujas done to such Holy objects produce merits which are equal to million times the Punyas(merit) obtained by worshiping "ordinary "man made God's idols.

Since,they are "Swayambhu"(self manifested)(it is believed) that the elaborate rituals of Prana Prathistha involving the Avahana Mantras and Avahanadi Mudras are not required .

Shalagramas are fossils found in the beds of Gandaki river ,Nepal and they represent Lord Vishnu.

Similarly ,Banalingas,found in Narmada riverbeds(in Madhya Pradesh) are considered as the corresponding "Swayambhu" forms of Lord Shiva.

But are these mere Hindu beliefs or are there confirmations available of these beliefs from Scriptures?

Answer 1

NO,not mere Hindu beliefs.That Shalagramas and Banalingas are really "Swayambhu" in nature are facts which are confirmed in Scriptures.

For,example,the following Sloka found in the Skanda Purana,confirms that Shalagramas are Swayambhu:

Shlalagramasilaayastu Prathistha Naiva Viddhate(Skanda Purana)

For Shalagrama Sila Pranaparthistha is not required.

Similarly,the following Sloka,from Bhavishya Purana,proves the same for Banalingas:

Banalingani Rajendra Khyatani Bhuvanatraye ||

Na Prathistha Na Sanskara Stesham Na Avahanam Tatha(Bhavishya Purana)||

The Banalingas are famous in the three worlds.They don't require Pranaprathistha,Sanskara or Avahanam.