RuneScape Classic Wiki
RuneScape Classic Wiki
The main RuneScape Wiki has an article on: Ceramic remains
The Old School RuneScape Wiki also has an article on Ceramic remains.

Ceramic remains are found randomly by digging at level 3 sites or by searching specimen trays in the Digsite. It is generally considered a useless item.

If used on the Archaeological expert he will say:

"Yes many parts are discovered. The inhabitants of these parts were great potters..."

Player: "You mean they were good as using potions ?"

Archaeological expert: "No no silly - they are were known for their skill with clay"[sic]