That's correct! Peridotite is a type of igneous rock that is composed almost entirely of dark silicate minerals, specifically olivine and pyroxene.

Here's why that's important:

* Composition: Peridotite's high olivine and pyroxene content gives it a dark green to black color and a dense, coarse-grained texture.

* Origin: Peridotite is found deep within the Earth's mantle, making it an important rock type for understanding the Earth's internal structure and composition.

* Role in Plate Tectonics: Peridotite plays a key role in plate tectonics. When it melts, it creates magma that rises to the surface and forms volcanic rocks.

Let me know if you have any other questions about peridotite!