SCIENCES!
Ice cubes have bubbles in because the outside freezes first and traps liquid inside. When the liquid freezes it releases the absorbed air and, since the air has nowhere to go, it creates bubbles.
Ice makers that make clear ice cubes have super cooled rods and flowing water runs over them. The ice is built up in small enough layers for the unfrozen water to carry away the bubbles of air that are released.
This probably froze over time where water hit rocks that were less than 0C, and the ice permeated out from the edge. In the middle, it is probably less clear.
SCINENSES!
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Cocodaye Miasere likes chips and peas, Thu 11 Dec 2014, 19:14,
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