Danalin's gem stone is the second reward from worshiping Danalin of Water. When used, it will send the message "Using magic, a tsunami is summoned and submerges the region!", converting tiles on the map to water tiles. It has a cooldown of an hour. If used in the overworld, tiles merely go transparent, with no effect on the corresponding map.
Wishing[]
danalin's gem stonewill create Danalin's gem stone, though this will only work in wizard mode.