Here's a little more detail:
* Dolerite is an intrusive igneous rock, meaning it cooled and solidified below the Earth's surface.
* It's formed from magma that cooled relatively quickly, resulting in a fine-grained texture.
* The distinctive dark grey to black color of Cradle Mountain is characteristic of dolerite.
The mountain itself is a large dolerite intrusion, formed millions of years ago when magma pushed its way up through the surrounding sedimentary rocks.
