Popcorn

Nodules of mineral deposits formed in such a way as to resemble popcorn.

Rimstone

A calcite deposit around the edge of a pool of water.

Sedimentary rock

Formed from deposits of sediments or from fragments of other minerals.

Shale

A sedimentary rock formed from deposits of clay or silt.

Solution

The process by which a substance is chemically combined with a liquid. Also, the state of being chemically so combined.