Whiskey Stones?

They don't cool the same way ice does. They cant possibly bring the temperature down a lot. Ice cools by removing heat from the drink to change the solid water into liquid. The stones are just removing enough heat to get themselves to equilibrium with the drink. You need a lot of stone to drink ratio. They just don't add water. I don't like the water in my drinks, so I like the stones. It helps to chill the glass first too.