hearthstone

noun

1. a stone forming a hearth.
2. home; fireside; hearth.
3. a soft stone, or a preparation of powdered stone and clay, used to whiten or scour hearths, steps, floors, etc.

noun

1. a stone that forms a hearth
2. a less common word for hearth (def. 1)
3. soft stone used to clean and whiten floors, steps, etc