Clue: Amorphous sulphur underneath rock made from mud is seen around Peru and Sweden (9)
Answer: SHAPELESS
Explanation: Definition: Amorphous
S(ulphur) underneath **SHALE** ("rock made from mud") seen around **.pe** (internet country demain for "Peru") + **S**(international car registration letter for "Sweden"), so **SHA(PE)LE-S-S