There isn't a specific rock type that is known for "absorbing" water in the same way a sponge does. However, some rocks are porous and can retain water within their structure:

* Sandstone: Composed of sand grains cemented together, sandstone can have many pores that hold water.

* Limestone: Formed from calcium carbonate, limestone can be porous and hold water, especially if it's fractured.

* Schist: A metamorphic rock with layers, schist can have open spaces between layers that hold water.

* Volcanic Rocks: Some volcanic rocks like basalt can be porous and hold water, especially if they are weathered.

Important Note: While these rocks can retain water, they don't "absorb" it in the same way as a sponge. The water is held within the pores and cracks of the rock.