Loading ...Lava cools into… Lava rock. Sometimes aged the rock is called Basalt. It varies in composition from very gassy, porous lava rock to very solid, concrete-like rock with no bubbles.
Hawaiians describe lava as two major types, depending on how it cools and flows. The cooling head of a flow will crumble many times, giving it a broken, cinder or clinker type of texture. We call this A’a lava. A more liquid, smooth hot lava that pools and cools slowly will have a satin smooth surface, sometimes with ropy swirls. We call this Paho’eho’e lava… black satin finish.
How long does it take to cool? That depends on the thermal mass behind the lava. When the fissures first cracked here, thick mud lava that had been stored underground since the 1955 eruption now surfaced. It was still hot.
On the surface, once a lava flow has stopped and is no longer being fed, it can take many months to a year or more before it is cool enough and safe enough to walk on. And the flows crack and split as they cool also, so it is not stable for a long time.