The design you see etched on the site of this bowl is the SHANKHA. It is also known to Western World as the Divine Conch.
Why a CONCH SHELL ON A SINGING BOWL?
Well, it is an important symbol in Hinduism and Buddhism.
In Hindu mythology, the shankha is a sacred emblem of Vishnu. The shankha is praised in Hindu scriptures as a giver of fame, longevity and prosperity and the cleanser of sin and impurities.
The conch shell is blown at the beginning of almost every Hindu ritual in Hinduism.
It has also found its way into Buddhism, as there is consideration that Buddha was one of Vishnu's incarnations. The shankha is one of the eight auspicious symbols of Buddhism, also known as Ashtamangala, and represents the pervasive sound of Buddhism.