Shalagram

Black stone containing an ammonite,
the spiral-shaped fossil shell of a prehistoric sea creature. The shalagram is primarily found in the upper reaches of the
Gandaki River in Nepal. The circular
ammonite fossil is understood to be
Vishnu’s chakra, and the shalagram is
thus understood as a “self-manifest”
(svayambhu) form of Vishnu. As with all
such “self-manifest” forms, the shalagram is believed to be especially holy,
since in it Vishnu has chosen to reveal
himself to his devotees (bhakta) rather
than coming to an image fashioned by
human hands. Because of its holiness,
the shalagram is often an object of worship. Its portability (and durability) made
it the preferred form of Vishnu for wandering Vaishnava ascetics. One also finds
cases in which small images are claimed
to have been revealed when a shalagram
was broken open; these images carry the
glamour of a finished image as well as the
divine power that accompanies spontaneous manifestation.