Rock salt; the mineral form of sodium chloride (NaCl); a sedimentary rock.
In stones, hardness most frequently refers to stone’s resistance to abrasion, particularly abrasion due to foot traffic, as tested by either ASTM C241 or C1353. In minerals, hardness generally refers to the mineral’s rank within the Moh’s Scale of Mineral Hardness.
The exposed surface of the jointed end of any given piece of stone with a gauged dimension not more than the minimum thickness of the material specified. Also known as “return head.”
1. The floor of a fireplace together with an adjacent area of fire-resistant material that extends into the room.
2. An area permanently floored with fire-resistant material beneath and surrounding a stove.
Originally the single large stone or stones used for the hearth, now most commonly used to describe the stone in front of the fire chamber and many times extending on either or both sides of the front of the fire chamber.
A satin-smooth surface finish with little or no gloss.
A residual or permanent volume change in stones after the temperature has been normalized, generally causing the stone panel to bow. Most commonly associated with fine grained true marbles used in thin panel applications.