Pottery of the time was low-fired and did not generally reach vitrification, and it was not glazed with a silica-based glaze that would seal it.
So over time this pottery would absorb water. And especially low-fired bits could totally break down.
Source: amateur ceramicist, and I have first-hand experience with cone 6 clay (vitrifies at 1200c) bisc-fired to cone 04 (1060c) and crumbling to bits when left in water too long.
So over time this pottery would absorb water. And especially low-fired bits could totally break down.
Source: amateur ceramicist, and I have first-hand experience with cone 6 clay (vitrifies at 1200c) bisc-fired to cone 04 (1060c) and crumbling to bits when left in water too long.