The Viski Glacier Rocks Hexagonal Basalt Stones are reusable drink-chilling stones made from basalt and shaped with six-sided geometry. They are used to cool spirits and other beverages without adding water from melting ice. Before use, the stones are chilled in a freezer, then placed directly into a glass with the beverage. Their solid construction provides a physical cooling medium ... https://www.bistrotorestro.com/glacier-rocks-hexagonal-basalt-stones-by-viski-876718049552