Rock
From UnReal World Wiki
Rocks are found scattered in the wilderness and are used to make arrows. They are more commonly found along shorelines.
As weapon, a rock counts as a crude club (you can train club skill by throwing rocks).
Not to be confused with stones, which are bigger and used for construction.
Settlements are a good place to collect rocks (and a few stones) because you can walk around quickly without obstacles. Another area with good amounts of rocks are hills and mountains which may be out of the way but are guaranteed to have them.