Jewellery — that is included in American range? (7)
I believe the answer is:
rockies
'american range?' is the definition.
(Rocky Mountains, a mountain range)
'jewellery that is included' is the wordplay.
'jewellery' becomes 'rocks' (informal term for jewels).
'that is' becomes 'i.e.' (synonyms).
'included' indicates putting letters inside.
'rocks' enclosing 'ie' is 'ROCKIES'.
'in' is the link.
(Other definitions for rockies that I've seen before include "North American mountain range" , "N. American mountains" , "Great mountains in western North America" , "US Mountain chain" , "US mountain range" .)