Something shiny in church where the Pope is (6)
I believe the answer is:
chrome
'something shiny' is the definition.
(chrome is a shiny material)
'church where the pope is' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'where the pope is' becomes 'Rome' (the Pope is the Bishop of Rome).
'ch'+'rome'='CHROME'
'in' is the link.
(Other definitions for chrome that I've seen before include "A yellow colouring matter" , "Feature of bath taps" , "Shiny metal for plating" , "Chinese callisthenic system" , "Silvery metal surface to prevent tarnishing" .)