Dodgy dealers pocketing money and gemstones (8)
I believe the answer is:
emeralds
'gemstones' is the definition.
(emerald is a kind of gemstone)
'dodgy dealers pocketing money' is the wordplay.
'dodgy' indicates an anagram (a dodgy or wrong order of the letters).
'pocketing' indicates putting letters inside (pocket can mean to steal or take possession of).
'money' becomes 'm' (abbreviation used in economics).
'dealers' anagrammed gives 'eeralds'.
'eeralds' enclosing 'm' is 'EMERALDS'.
'and' acts as a link.
(Other definitions for emeralds that I've seen before include "Mere lads (anag.)" , "They're preciously green on the Isle" , "Green stones from strangely red males" , "Precious stones for odd red males" , "Green gems" .)