Molten lava is called as a stone during a volcanic eruption, and stone, which has hardened and cooled down after the eruption. Emerging from the crater of the volcano, the lava has the form of a liquid with a temperature of 700-1200 ° C. Before you solidify and cool down, the lava, which has a viscosity in the 100 000 times more than water, can spread over great distances. The lava flow – is the current lava, which is created during the effusive eruption. When the lava stops flowing, it hardens and forms a volcanic rock. In general, the composition of the lava determines its behavior more than the temperature of the eruption.