Use clear lake, pond ice or try boiling water for 3 minutes let the water cool; then boil for 3 minutes again and let cool to remove gas. Create a foil container 2" deep and freeze slowly. Or buy a clear block of ice. To make fire, the ice must be clear. Look at the bottom of http://primitiveways.com/fire_from_ice.html to see a Big ice lens.
http://www.instructables.com/id/Making-Fire-With-Ice!/