Akkadian

ḫiṣṣu - gravel (CAD Ḫ 204, AHw. 349)

is likely an Aramaism

PWS
*ḥVṣ-; *ḥVṣVṣ- - pebble, gravel (Fronzaroli 1968: 271, 287, 298; Kogan 2011: 190)