Lava Meeting the Pacific Ocean 

When lava hits water, it is cooled quickly which gives it a different appearance. It turns out looking dark and has a glass like appearance. It is the same which most extrusive igneous rocks, meaning rock that is made from molten rock material that cools on the surface of Earth, and not underneath the Earth. Also, the hot lava may take on saline water from the ocean, therefore altering the overall mineral composition.