Clue: Head appearing stoned in India, back in the day? (5,2,3,5)
Answer: JEWEL IN THE CROWN
Explanation: Definition: India, back in the day?

JEWEL ("stone") IN THE CROWN ("head") 
 

 
*During the days of the British Empire, India was seen as the most valuable of Britain's overseas "assets", and was nicknamed the Jewel in the Crown.