It is said that Goddess Lakshmi resides in Dakshinavarti Shankh (Orange), thats why worshipping this shankh means worshipping Goddess Lakshmi herself and she will shower her blessings on the one who worships it. It endows the devotee with abundance of wealth and prosperity.
Dakshinavarti Shankh (Orange), Valampuri Sanggu; Tamil: or Sri Lakshmi Shankh, is a sacred Hindu object otherwise known in English as a conch shell. This is the shell of a large sea snail from the Indian Ocean (a shell of the species Turbinella pyrum), but one that has the very rare reverse-turning spiral.
In other words, when it is held with the spout (siphonal canal) pointed up, this conchs spiral twists rightwards (dakshinavarti) rather than very much more common form, which twists leftwards (vamavarti).