معنى يشب، يشم حجر كريم في القاموس

Pumice stone

Of precious or semi precious stones (natural, synthetic or reconstructed)

DUST AND POWDER OF NATURAL OR SYNTHETIC PRECIOUS OR SEMI-PRECIOUS STONES

SETTS, CURBSTONES AND FLAGSTONES, OF NATURAL STONE (EXCEPT SLATE)

ARTICLES OF CEMENT, OF CONCRETE OR OF ARTIFICIAL STONE, WHETHER OR NOT REINFORCED