Rimstone vs. Flowstone — What's the Difference?

Rimstone, also called gours, is a type of speleothem (cave formation) in the form of a stone dam. Rimstone is made up of calcite and other minerals that build up in cave pools.

Flowstones are composed of sheetlike deposits of calcite or other carbonate minerals, formed where water flows down the walls or along the floors of a cave. They are typically found in "solution caves", in limestone, where they are the most common speleothem.

A secondary mineral deposit, with a stone-wall-like appearance made up of calcite and other minerals, that builds up to create cave pools.

A layered deposit of calcium carbonate or another mineral, formed by water flowing along the walls or floor of a cave. Also called dripstone.

(geology) A secondary layered mineral deposit of calcite or other mineral, formed by water flowing down the walls and along the floor of a cave.