Ice glass

A decorative effect that causes the surface of the glass to resemble cracked ice. This is achieved by repeatedly plunging a parison of hot glass into cold water and withdrawing it quickly. The thermal shock creates fissures in the surface, and these impart a frosted appearance after the parison has been reheated to allow the forming process to continue.

plunging hot bubble into water to create fissures
Aspersorium
Aspersorium full length video recreating entire object