icetigris:

Shades of Turquoise Ice

In the winter, for about five months or from January to May, the lake freezes over but the water is so clear that, from the surface, you can see an astounding 130 feet below you. Transparent and shining in a turquoise color, these masses of broken ice look like shards of glass rising into the sky. They are caused by the slow and unequal pressure in the main body of the packed ice as well as by the unequal structure and temperature.