Organ Pipes National Park: Part 6

A photograph of a scoria rock

A photograph of scoria, a description of the rock and a description of how it was formed.

Scoria is a less technical term for macrovesicular volcanic rock and it is commonly basaltic or andestic in composition. Scoria is considered light but has a gravity more than one and sinks in water. Scoria differs in the textural tone than other volcanic rocks because they have larger vesicles and thicker vesicle walls and is often darker in colour (dark brown, black or red).

Scoria is a rock full of bubble holes and the bubble holes were formed as the lava spewed out of the volcano and were trapped as the lava cooled and hardened.