The Sacred Conch
Śaṅkha (Sanskrit; Tamil: cankam) is the divine conch held by Bhagavān Viṣṇu in one of His four hands. It is both a weapon (producing the primordial sound that defeats evil) and a liturgical instrument — blown at the beginning of worship to sanctify the space and announce the divine presence.
Śaṅkha and Cakra Marks
At pañca-saṃskāra initiation, the right shoulder is branded with the heated cakra (discus) mark and the left with the heated conch (śaṅkha) mark. These marks (tāpa) signify that the devotee's body belongs to Bhagavān — it bears His insignia permanently. The branding is done with hot metal implements shaped as the śaṅkha and cakra.
In Worship
The śaṅkha is blown during major worship services, processions, and festivals. The sound of the conch is considered purifying — it drives away malevolent forces and announces the Lord's presence. The Pāñcajanya (Kṛṣṇa's conch) is the pre-eminent śaṅkha in the tradition.