The types of Shilajit is characterised from the type of mountainous rocks from which it exudes:

Rocks containing Gold :

Shilajit oozing out of these rocks have reddish colour..

Rocks containing Silver (Rajat Shilajit):

Shilajit coming out of these rocks are whitish in colour.

Rocks containing Copper:

The exudation from these types of rocks has a peacock-throat like appearance, i.e. bluish-purple colour.

Rocks containing Iron:

Considered as the best variety, the exudation looks quite similar to the gum.