A dark volcanic rock rich in iron and magnesium minerals. Basalt is the most common volcanic rock on earth.

A rock fragment or grain resulting from the breakdown of larger rocks.

A sedimentary rock made of a mixture of rounded pieces of other rocks.

A sheet or wall-like mass of igneous rock that cuts across other rocks.

A rock that was carried along the base of a glacier and dropped, most commonly into a sedimentary layer, as the glacier melted.