nipatan sa giris tatra
curnayam asa mahata
nipatan—falling down; sah—that; girih—mountain; tatra—there; bahun—many; amara-danavan—demigods and demons; curnayam asa—were smashed; mahata—by great; bharena—weight; kanaka-acalah—the golden mountain known as Mandara.
The mountain known as Mandara, which was extremely heavy, being made of gold, fell and smashed many demigods and demons.
By constitution, gold is heavier than stone. Since Mandara Mountain was made of gold and was therefore heavier than stone, the demigods and demons could not properly carry it to the ocean of milk.
Link to this page: https://prabhupadabooks.com/sb/8/6/35