. Igneous rock is formed through the cooling and solidification of magma<span> or </span>lava<span>. The magma can be derived from </span>partial melts<span> of existing rocks in either a </span>planet<span>'s </span>mantle<span> or </span>crust<span>. Typically, the melting is caused by one or more of three processes: an increase in </span>temperature<span>, a decrease in </span>pressure<span>, or a change in composition. In this case, the "rock" is ice. The hot water has cooled through a change of temperature to create a solid structure (ice).</span>