Whiskey stones made from basalt natural basalt rock and laser engraved on the top-side of favorite Michigan themed images. These stones are used for ANY drink that you wish to stay cold and not dilute the drink flavor. The engraved images are on a single cube side. Due to the small surface area available for the image, the engraving is small and fine detail is removed. The image is best seen with the stones are wet. 1" x 1" 9-Piece Whiskey Stone Set Cleaning Instructions: Hand wash only. Whiskey stones are made from basalt, a natural occurring volcanic rock. Color can vary from black to gray and have random streaks on the surface. Put whiskey stones in your freezer, and add to a drink that is ALREADY cold. Stones come with a black velvet pouch and in a gift box.