Kaustubha

In Hindu mythology, the gem that the
god Vishnu wears on his chest. The
Kaustubha jewel is one of the precious
things produced by churning the ocean
of milk. Other products include the goddess Lakshmi, the Kamadhenu or wishing-cow, and the nectar of immortality
(amrta). Vishnu’s possession of the
Kaustubha jewel is a symbol of his
power and his mastery over the universe. See also Tortoise avatar.