A property of two or more liquids that can be mixed to form a homogeneous solution. Liquids that fail to form a solution when mixed in certain proportions are said to be immiscible. Oil and water are immiscible in all proportions, ethanol and water are miscible in all proportions, but diethyl ether and water form a solution in some proportions, but not in others, so they are immiscible. Immiscible metals will not form alloys; they will mix when molten but separate as they cool. Similarly, some magmas contain immiscible rocks that separate as the magma cools.