Stone location determined in routine of duty (7)
I believe the answer is:
rosetta
'stone location' is the definition.
'rosetta' can be an answer for 'stone' (I've seen this before). I'm not certain of the 'location' bit.
'determined in routine of duty' is the wordplay.
'determined' becomes 'set' (synonyms).
'in' indicates putting letters inside.
'routine of duty' becomes 'rota' (I can't justify this - if you can you should give a lot more credence to this answer).
'set' placed within 'rota' is 'ROSETTA'.
Can you help me to learn more?
(Other definitions for rosetta that I've seen before include "town of old on the Nile" , "Inscribed basalt slab (found 1799), key to deciphering Egyptian hieroglyphs" , "Tablet that was the key to deciphering Egyptian hieroglyphs" , "Source of revelatory stone" , "Source of museum item" .)