I packed icy snow into a 1/2 gallon yogurt container and then dusted it with a thin coat (less than half a millimeter) of volcanic ash from Redoubt's April 4th eruption. There are two days of time-lapse in this video. The first was zoomed out a bit looking down on the ash, and the second is a macro lens up close and oblique. After the water from the first day of melting froze over night the style of melting changed a lot.